Contents Hospital Isolation Equipment - Eaton

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Hospital Isolation Equipment Medical Systems

36.0-1

Hospital Isolation Equipment

Ref. No. 1313

Contents Description

Page

Hospital Isolation Equipment General Description of Product Family . . . . . . . . . . . . . . . . . . . . . . . . . . . 36.0-2 Advantages of Isolated Power Systems (IPS) . . . . . . . . . . . . . . . . . . . . . . 36.0-3 Isolated Power Panels (Type IPP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36.0-6 Isolated Power Centers (Type IPC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36.0-7 X-Ray and Laser Power Centers (Types XPC and LPC) . . . . . . . . . . . . . . . 36.0-8 Surgical Facility Centers (Type SFC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36.0-9 Line Isolation Monitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36.0-10 Specifications For complete product specifications in CSI format see Eaton’s Cutler-Hammer Product Specification Guide. . . . . . . . . . . . . Section 16473

36

Line Isolation Monitors

CA08104001E

For more information visit: www.cutler-hammer.eaton.com

PIN 0951700

36.0-2 Hospital Isolation Equipment Medical Systems

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January 2003 Ref. No. 1314

General Description

Medical Systems

Surgical Facility Centers G

Eaton’s Cutler-Hammer business, the leader in electrical distribution products, has teamed with Isotrol Systems, a division of Bender, to offer a complete line of electrical products for use in the healthcare industry. All products meet or exceed ULT, CSAT and NFPA standards. The entire product family integrates the use of isolated power supplies, continuous monitoring for hazardous conditions, and testing of circuit conditions with maximum selectivity of tripping overcurrent devices when hazards develop, and highest patient and operator safety. Isolated Power Systems are typically used in the emergency electrical distribution circuits associated with Life Safety and Critical Care areas within a health care facility. See Figure 36.0-1 for details. For further details reference the IEEE White Book — Recommended Practice for Electrical Systems in Health Care Facilities — ANSI/IEEE Standard 602. A brief description of select IPS products and their purpose follows.

Isolated Power Panels and Power Centers Type IPP Isolated Power Panels are designed to provide isolated power to electrical circuits installed in operating rooms and other electrically susceptible patient care areas. Each IPP includes a single- or 3-phase transformer, a Line Isolation Monitor (LIM), a reference ground bus, a primary circuit breaker, and a number of branch circuit breakers all in a #14 gauge galvanized steel box with #14 gauge stainless steel (#304) cover with a brushed finish. Single-phase applications are available from 3 – 25 kVA, and 3-phase applications are available from 10 – 25 kVA. For more IPP details see Page 36.0-6.

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From Normal Distribution

Description Critical Branch Emergency System Life Safety Branch Distribution Panelboard Isolated Power Panel

Emergency System Receptacles •Color or marking •Panelboard + Circuit # •Hospital Grade (green dot)

Critical Care Area

Figure 36.0-1. Health Care Facility — Simplified Power Distribution Arrangement Type IPC Isolated Power Centers are identical to the IPP product with the addition of an eight gang section for Hospital Grade power receptacles and ground jacks. For more IPC details see Page 36.0-7. The LIM integral to each IPP or IPC displays the incremental changes in ground leakage current as additional medical apparatus is plugged into the receptacles and displays the total system leakage current that will flow through a solidly grounded person who comes in contact with an energized phase conductor either directly or through an insulation failure.

X-Ray and Laser Isolated Power Centers Types XPC and LPC X-Ray and Laser Isolated Power Centers are designed to provide isolated power to x-ray and laser receptacles within operating rooms and other electrically susceptible areas. Each XPC and LPC includes a single- or 3-phase transformer, a Line Isolation Monitor (LIM), a reference ground bus, a main breaker, branch breakers, contactors, selector station with pushbuttons and LED indicating lights, and a Programmable Logic Controller (PLC) all contained within a #14 gauge box and stainless steel (#304) cover. For more details on the XPC and LPC product, see Page 36.0-8.


Type SFC Surgical Facility Centers are designed to provide isolated power to electrical circuits installed within operating rooms and other electrically susceptible patient care areas. Each SFC includes a single-phase transformer, a Line Isolation Monitor (LIM), a reference ground bus, a primary breaker, up to 16 branch breakers, up to eight Hospital Grade power receptacles, up to eight Hospital Grade ground jacks, a two-section X-Ray Viewer, a clock and elapsed timer, and an AM/FM stereo system with cassette and/or CD player. All equipment is mounted in a #12 gauge galvanized steel box with #12 gauge stainless steel (#304) brushed cover on the SFC product, see Page 36.0-9.

Line Isolation Monitors Type LIM Line Isolation Monitors are available for single-phase or 3-phase applications, 50 or 60 Hz, 24, 100, 110, 120, 200, 208, 220, 230, 240 and 277V AC system voltages. Two separate ground connections are provided for added safety when the LIM is wired into an Isolated Power System (IPP, IPC, XPC, LPC or SFC). The LIM measures and displays the total hazard current (leakage current) for all medical equipment connected to the branch circuit wiring on an analog or digital panel meter. A visual and audible alarm occurs when the hazard current exceeds 2 or 5 milliamperes. The audible alarm may be muted, however the visual alarm remains on for the duration of the high total hazard current. A test switch can be activated to verify that the LIM is operating properly. The LIM has provisions for connecting one or more remote stations installed close to patient care areas. For more information on the LIM see Page 36.0-10.

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36.0-3

Ref. No. 1315

Application Information — IPS

Advantages of Isolated Power Systems (IPS) Isolated Power Systems (IPS) were first introduced into the hospital environment as a means of reducing the risk of explosions in operating rooms and other areas containing or using flammable anesthetizing agents. The IPS functions by “floating” the secondary power lines so that ground faults, the primary source of equipment failure, can be recognized at an early stage, in a condition where they do not present first fault personal shock or incendiary hazards. IPS systems offer additional advantages to system security and operational safety for both operators and patients. The isolated power system is recognized as the safest possible system and does provide an additional layer of safety to both patient and operator alike. Today, hospitals no longer use flammable anesthetizing agents, and the use of isolated power is currently recommended only for use in “wet locations” where the loss of equipment power cannot be tolerated. Reference to these facts may be found in the Health Care Facilities Handbook (Second Edition), and on page 214, Chapter 6, of the IEEE Recommended Practice for Electric Systems in Health Care Facilities (The IEEE white book) ANSI/IEEE Standard 602-1986. The following discussion explains the advantages that IPS systems offer over conventional grounded systems and the Ground Fault Circuit Interrupter (GFCI).

The Grounded System Figure 36.0-2 shows a conventional grounded system. The neutral of the transformer is bonded to ground. In Figure 36.0-3, we assume that a person has a body resistance of 1000 ohms. If the 1000-ohm body touches the line L, a current of 120 mA could flow from the line conductor, through the 1000ohm person, and return to the system via the low impedance neutral-ground connection. This 120 mA could prove dangerous to such a 1000-ohm person.

Table 36.0-1. Comparison of Voltage Across and Current Flowing Through a Person

L N

120V 208V

1000Ω

120V G

0V

Figure 36.0-2. Conventional Grounded System has One Side of Power Line Connected to Ground. If the 1000-ohm Person Touches the Line (L), he will have 120 mA of Current Flowing Through his/her Body 50µA L1 L2

120V 208V 60V

C1 I

1000Ω

C2 G

Figure 36.0-3. Isolated Power System with 1000-ohm Person. Secondary Side has No Resistive Path to Ground, so if System Net Capacitance is Low, Human Could Contact Either Side of Power Line Safely 120V L2

L1 60V

60V 50µA

Figure 36.0-4. Schematic Representation of Typical Distributed Capacitance in an IPS 120V L1 I 1000Ω

V1 C1 2.21 nF

L2 V2 C2 2.21 nF

Figure 36.0-5. Equates to the Circuit Below 120V L1 C1

L2 C2

1000Ω

Figure 36.0-6. 1000-ohm Person in Contact with One Line Conductor and Ground

Should the person have less ohmic resistance, due to excessive moisture or internal body connections, larger and more lethal currents could flow through his/her body should he/she come into contact with line L.

CA08104001E


Scenario Grounded IPS Voltage over Person

120V

0.1V (with 50 microamp initial leakage)

Current thru Person

120 mA

100 microamp (with 50 microamp initial leakage)

The Isolated Power System (IPS) Figure 36.0-3 shows an isolated power system. There is no intentional ohmic connection between the supply (neutral) and ground. The 1000-ohm person has greater protection from potentially lethal shock hazard because of the absence of the low impedance ground-system return path. However, there is always a “capacitive” path to ground because of the inherent system net capacitance between any line conductor and ground. Figure 36.0-4 assumes a typical equally distributed, balanced capacitive system with small leakage current (50 microamps) flowing from L1 via C1, through the ground, and returning to L2 via C2. We can measure the voltage drop across the system capacitance by using a high impedance voltmeter. In a balanced system as shown, we can expect to measure 60 volts from each line to ground. Leakage current may at this time be measured by connecting an mA or microamp meter from either L1 or L2 to ground. The 50µA assumed current means that each capacitance has an impedance of 1.2 x 106 ohms (Z = V/I = 60/(50 x 10-6) = 1.2 x 106 ohms). (50µA is assumed because it represents a typical light load system leakage to ground.) 50 µA current corresponds to a capacitance of C = 2.2 x 10-9 F or .002µF (at 60 Hz). Now, should our 1000-ohm person come into contact with either side of the line, the maximum current that could flow through him/her would be only 100µA as seen in Figure 36.0-4. Our 1000-ohm person coming into contact with L1 has shunted one side of the high impedance paths to ground, and therefore will approximately double the leakage current to 100 microamps, which is still an extremely low level for all but subcutaneous patient leakage paths.

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Ref. No. 1316

Application Information — IPS Voltage across the person would be: 1000 - x120 = 0.1V ---------------------1201000 Voltage across C2 would be: 6

1.2x10 - x 120 = 119.9V --------------------1201000

Current passing through our 1000-ohm person would be: 120V ----------------------- = 100microamps 1201000 Table 36.0-1 compares the effect of the grounded system vs. IPS with a grounded 1000-ohm person in contact with a line conductor of each system.

The Line Isolation Monitor The Line Isolation Monitor (LIM) is a device which continually monitors the impedance (resistance and capacitance) from all lines (single- and 3-phase) to ground, and indicates the maximum current that could flow to a patient, should the patient come into contact with the line conductor (i.e., defective equipment). Note: many variables affect what current could actually flow to the patient:

The isolated system does not have any low-impedance connection to ground. It has a high-impedance capacitive/ resistive return path. This provides the layer of electrical safety that protects both operators and patients alike.

Continuity of Supply Probably the strongest argument for the use of isolated power is where continuity of supply is paramount. Article 517-20 (1996 NEC) Wet Locations states: “All receptacles and fixed equipment within the area of the wet location shall have ground-fault circuitinterrupter protection for personnel if interruption of power under fault conditions can be tolerated, or be served by an isolated power system if such interruption cannot be tolerated.” Let us examine the advantages of the IPS system to see how it compares with the alternatives: the grounded system and the GFCI (ground-fault circuit interrupter). Figure 36.0-7 is a schematic representation of both grounded and ungrounded power systems.

2. Parallel leakage return paths will also bypass a portion of the leakage current from the patient.

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ICU and CCU areas, where the patient may be connected to several pieces of equipment (all of which contain their respective leakages, both resistive and capacitive) greatly add to the possibility of hazardous leakage currents flowing. We must never neglect the fact that a leakage on a grounded system will return via the low impedance neutral-ground connection. The magnitude of this current is limited only by the impedance of the parallel paths to ground — for example, our 1000-ohm person.

When we compare the same situation with the ungrounded system: Fault F 2 (same location as F1) will cause a very small current Ic to flow to ground and return to the source via the system capacitance. The magnitude of Ic is limited by circuit and fault impedance which, in this case, is the system capacitance (assumed to be .002µF). Ic= 120V/(1.2 x 106Ω) = 100 microamps During fault F2, the line isolation monitor would quickly alarm the fault condition so that remedial action may be taken — but no fuses or circuit breakers will trip. Supply continuity has been maintained by using an IPS.

Isolated Power vs. GFCI L

1. The value of 1000 ohms may vary between less than 100 ohms to 20,000 ohms, depending on the condition of the patient (moisture content, muscle condition, dry skin, etc.).

In the grounded system we see that fault F1 will cause a large short-circuit current (Isc) to flow to ground and return to the supply by the equipotential ground (G) and the neutral bond. The magnitude of this current will be limited only by the circuit and fault impedance, and typically will be in the thousands of amperes range. Obviously, fuse F will quickly blow or, in the case of a circuit breaker, quickly trip.

Fuse F

F1

Source

Load

N G

Isc

The ground-fault circuit interrupter (Figure 36.0-8) is a device that may be installed with a grounded power system. It reacts by tripping a circuit breaker should leakage current exceed the GFCI rating.

A

CB

Iout L

L1 Source

F2

Source

Load

L2 G

GFCI

Ic

B

Figure 36.0-7. Schematic Representation of Both Grounded (A) and Ungrounded (B) Power Systems


Iin

∆I

N G

Figure 36.0-8. Schematic of GFCI Application The unit operates simply by comparing the current flowing out to the load against current returning from the load. If both currents are equal, their resultant sum is zero; the circuit operates correctly.

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36.0-5

Ref. No. 1317

Application Information — IPS

Should the two currents not equal zero — i.e., a portion of the current returns to the source via another path, a residual current will be detected by the GFCI. Should this residual current be in excess of the GFCI trip rating (5 mA), the breaker will operate and cut off power to the circuit. Important — the GFCI does not provide continuous and advanced monitoring of equipment and circuit condition, nor does it alert impending problems. The unit will simply trip without warning, and may be prone to nuisance tripping during erratic supply conditions.

Figure 36.0-10 represents the corresponding fault impedance diagram.

Isc 350A

208V 60 A.C.B. 5.1%

Isc 607A

120V 20 A.C.B.

60 A.C.B. Z Cable

Isc 2300A

20 A.C.B.

Z Cable

Z Cable

Fault

Fault

IPS System

Short-Circuit Currents

120V Isc 2300A

Grounded System

Extremely large short-circuit currents can flow in grounded systems (nonIPS) during a line-to-line or a lineto-ground fault condition. We shall now examine how the IPS can reduce these large and damaging short-circuit currents, which helps prevent a total system outage that could affect a large area of the hospital.

Figure 36.0-10. IPS (left) and Grounded System (right) Reduced to Fault Path Components

Figure 36.0-9 shows a one-line for both a grounded and an IPS distribution system.

Calculations assume the above conditions with 208/120V transformer with 0.051 pu reactance and the infinite bus at system input. Cable impedance is assumed for 2 conductor, #12 AWG.

208V

120V

60A

60A

Figure 36.0-10 shows the instantaneous currents that flow, and helps predict circuit breaker clearing.

5 kVA

120V 20A IPS System

Assume a short-circuit fault occurs on a piece of equipment connected via a 10-foot (3 m) cable to the output 20 ampere circuit breaker of each system, and compare the results.

120V 20A Grounded System

Figure 36.0-9. Typical Distribution Arrangement for IPS (left) and Grounded Systems (right)

Comparison of the two systems show that the IPS system experiences reduced magnitude of short-circuit current by a factor of approximately 4:1 on the secondary side of our two systems, and 7:1 on the primary side. Obviously, fault energy dissipation damage is proportionally reduced using IPS. In this example, only one circuit on the IPS system, the faulty piece of equipment, would be disconnected. All other secondary circuits would be unaffected by this fault condition. When we compare tripping of breakers with the grounded system, the 60 ampere breaker will trip and all secondary 20 ampere circuits and connected equipment could be affected by power loss. Remember that in normal installations, this main 60 ampere breaker could be feeding several circuits or several beds in an ICU or CCU.

CA08104001E


The advantages of the IPS system in both reduced energy dissipation at the point of fault, and continuity of supply for the connected consumers are apparent.

Noise Reduction Increased use of sensitive electronic systems in the hospital environment has created a growing need to supply these systems with “clean” voltage, free of noise and transients. Many data storage and monitoring equipment are sensitive to line transients and line noise frequently present on voltage feeders. Noise has many sources — lightning strikes, switching surges, motors, SCRs, switched mode power supplies, and discharge lighting, to name but a few. Many manufacturers of voltage-sensitive equipment have recognized the problem created by transients and noise on their equipment’s input line and have provided a measure of protection as an integral part of their equipment. This protection, however, may not be adequate for frequent or serious disturbances. The IPS system contains a quality shielded isolation transformer which provides a convenient and effective means of reducing or even eliminating line-to-line and line-to-ground noise on voltage feeders. The IPS’s shielded isolation transformer can provide a 50 – 70 dB attenuation of wideband line-to-ground (common-mode) noise. Note: dB = 20 log (V1/V2).

As an example, a large 1500V transient having a frequency of about 750 kHz, will be reduced by a factor of 3162.3 (70 dB) to a value of 0.47V by the shielded isolation transformer. Although the primary reason for the IPS design and installation was not to achieve this attenuation, rather to provide a low leakage secondary power system, this is another “builtin” advantage when comparing isolated power with conventionally grounded systems.

36


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Ref. No. 1318

Technical Data

Isolated Power Panels (Type IPP)

Table 36.0-3. IPP Dimensions

w

1-inch (25.4 mm) Plan W

Dimensions in Inches (mm) h

w

d

H

W

C

48 (1219)

30 (762)

14 (356)

50 (1270)

32 (813)

a S/S front trim.

1-inch (25.4 mm)

b Backbox, galvanized steel.

d

A

Backbox Type

c Hat section, galvanized steel. o

d Branch breaker subchassis. e Breaker deadfront.

k

h

H

f Hinged door over circuit breakers. g LIM circuit breaker.

l

i g

m

j

Circuit Breakers

h

h Loadcenter.

d

i Primary circuit breakers, 1-, 2-, or 3-phase.

n

f

j Branch circuit breakers, 1-, 2-, or 3-phase.

e A

c

a

Front

b View A-A

k Isolation transformer: Phases 1-Ph Power rating: Primary voltage: Secondary voltage: Frequency:

Figure 36.0-11. Outline Drawing for IPPs Single- and Three-Phase 10 to 25 kVA i Note: The 3-phase isolation transformer is available in delta-delta and wye-delta configuration.

Incoming Power

k

L1

L2

L3

}

1

2

3

4

5

6

7

8

j

kVA V V Hz

l Line isolation monitor, 1- or 3-phase, analog or digital. LZ Series LIM

l

m LIM connector plate. To System Ground

L1 L2 12 Vac Com * M* M+ RI1 K1/NC K1/Com K1/NO Safe Hazard RI2 GND2 LIM GND Test/L3

OR

}

h

3-Ph

n Reference ground bus.

* Metered Remote Only To Remote Indicator Series MK2450 (if required)

n

o Vent-holes for convection air flow.

Panel Ground

n

9 10 g

36

Figure 36.0-12. Wiring Diagram for IPPs Three-Phase 10 to 25 kVA Table 36.0-2. IPP Ratings Transformer kVA Ratings 1

Voltages Volts AC

Branch Breakers

Single-Phase

Three-Phase

Primary

Secondary

Single-Phase

Three-Phase

3 5 7-1/2 10 15 20 25

15 20 25

120 208 220 230 240 277 380 400 480

120 208 220 230 240

14 Maximum 2-Pole (Plug-in or Bolt-on)

10 Maximum 3-Pole (Plug-in or Bolt-on)

1

Backbox size is reduced to 41-inch H x 24-inch W x 8-inch D (1041.4 mm H x 609.6 mm W x 203.2 mm D) for 3, 5, 7-1/2 and 10 kVA transformers.


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36.0-7

Ref. No. 1319

Technical Data

Isolated Power Centers (Type IPC)

Table 36.0-5. IPC Dimensions

w

1-inch (25.4 mm) Plan

1-inch (25.4 mm)

W


w

d

H

W

B

41 (1041)

24 (610)

8 (203)

43 (1092)

26 (660)

a S/S front trim.

d

A

Backbox Type

b Backbox, galvanized steel. c Backplate, galvanized steel. d Branch breaker subchassis.

k

i

f Hinged door over circuit breakers.

h

H

e Breaker deadfront. c

g

l m

j

h Loadcenter.

d

n

f

g LIM circuit breaker.

h

i Primary circuit breakers, 1- or 2-phase.

e

j Branch circuit breaker, 2-phase.

a A

o

b

p View A-A

Front

Figure 36.0-13. Outline Drawing for IPCs Single- and Three-Phase 10 to 25 kVA

i

X1

H1

X2

IZ Series LIM

l Line isolation monitor, 1-phase, analog or digital.

l

Incoming Power

j

H2

k h

L1 L2 12 Vac Com MM+ RI1

OR

1

2

3

4

5

6

7

8

9

10

11

12

K1/NC K1/Com K1/N0 Safe Hazard R12 GND2 LIM GND Test/L3

g

k Isolation transformer: Phases 1-Ph Power rating: kVA Primary voltage: V Secondary voltage: V Frequency: Hz

m LIM connector plate. * *

* Metered Remote Only

n Ground bus.

To System To Remote Ground Indicator Series MK2450 (if required)

o Hospital grade power receptacles. p Hospital grade ground jacks.

m

n

Panel Ground

o

p

36

Figure 36.0-14. Wiring Diagram for IPCs Three-Phase 10 to 25 kVA Table 36.0-4. IPC Ratings Transformer kVA Ratings

Voltages Volts AC

Single-Phase

Three-Phase

Primary

Secondary

Single-Phase

3 5 7-1/2 10

N/A

120 208 220 230 240 277 380 400 480

120 208 220 230 240

16 Maximum 2-Pole (Plug-in Only)

CA08104001E

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Ref. No. 1320

Technical Data

X-Ray and Laser Power Centers (Types XPC and LPC)

Table 36.0-7. XPC/LPC Dimensions

w


w

d

H

W

C

48 (1219)

30 (762)

14 (356)

50 (1270)

32 (813)

a S/S front trim.

1-inch (25.4 mm) Plan W

Backbox Type


d A

c Hat section, galvanized steel. d Branch breaker subchassis.

o k

e Breaker deadfront. f Hinged door over circuit breakers.

H

g LIM circuit breaker.

h

i g j

C1 C2

q

C4

C5 C6 C7 C8

l m

Branch Circuit Breakers

f

n

A

h Loadcenter.

h

i Primary circuit breakers, 1-, 2-, or 3-phase.

d

e

p a

j Branch circuit breakers, 2- or 3-phase.

c b

Front

View A-A

Figure 36.0-15. Outline Drawing for XPC/LPC Single- and Three-Phase 10 to 25 kVA X-Ray and Laser Isolated Power Center Power Section


3-Ph kVA V V Hz

l Line isolation monitor, 1- or 3-phase, analog or digital.

Control Section

XFMR

Output

PLC

Input

m LIM connector plate. LIM

n Reference ground bus. Nurse Station

o Vent-holes for convection air flow.

Contactor

p Programmable logic controller (PLC). q Secondary circuit contactor (C1…C8).

Display Outlet Remote Indicator

Outlet Device

Door Contact

In-Use Lamp

X-Ray and Laser Receptacle Module

36

Figure 36.0-16. Typical Circuit Arrangement for XPC/LPC Table 36.0-6. XPC/LPC Ratings Transformer kVA Ratings

Voltages Volts AC

Single-Phase

Three-Phase

Primary

Secondary

Branch Breakers Single-Phase

Three-Phase

10 15 20 25

10 15 20 25

120 208 220 230 240 277 380 400 480

120 208 220 230 240




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36.0-9

Ref. No. 1321

Technical Data

Surgical Facility Centers (Type SFC) b

Table 36.0-9. SFC Dimensions

w

d

k

e

A

B

B

h

w

d

H

W

D

42 (1067)

50 (1270)

8 (203)

44 (1118)

52 (1320)


d

t

12:00

00:00

l

c Power supply for stereo system.

q

d Branch breaker subchassis.

i

e Breaker deadfront. n

H

f

h

r

g

f Hinged door over circuit breakers. g LIM circuit breaker. h Loadcenter.

a

i Primary circuit breakers, 1- or 2-phase.

j

o A

p

m

1-inch (25.4 mm)

W

View B-B

Front

Figure 36.0-17. Outline Drawing for SFCs Single-Phase 3 to 10 kVA

i

H2

X1

H1

X2

j

IZ Series LIM

k h

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

To System Ground

L1 L2 12 VAC Com * M* M+ RI1

* Metered Remote Only

g

To Remote Indicator Series MK2450 (if required)

K1/NC K1/Com K1/N0 Safe Hazard R12 GND2 LIM GND Test/L3

m

o

st

Panel Ground

kVA V V Hz

c

p

n Reference ground bus. o Hospital grade power receptacles. p Hospital grade ground jacks. q Stereo system.

n

To Clock, Elapsed Timer and Control Station (For Wiring Details, see Data Sheet on ZT1491 Clock/Elapsed Timer)

AC DC

X-Ray Viewer


m LIM connector plate.

OR

1

j Branch circuit breaker, 2-phase.

l Line isolation monitor, 1-phase, analog or digital.

l

Incoming Power

To Existing Roof Antenna

r Speakers. s Clock. t Elapsed timer. Clock/elapsed timer remote control. X-ray viewer.

Radio

r

q

36

Figure 36.0-18. Wiring Diagram for SFCs Single-Phase 3 to 10 kVA Table 36.0-8. SFC Ratings Transformer kVA Ratings

Voltages Volts AC

Single-Phase

Three-Phase

Primary

Secondary

Single-Phase

3 5 7-1/2 15

N/A

120 208 220 230 240 277 380 400 480

120 208 220 230 240


CA08104001E

Dimensions in Inches (mm)

a S/S front trim.

View B-B

s

Backbox Type

Branch Breakers



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Technical Data

Line Isolation Monitors (Type LIM)

LIM Features ■ ■ ■

■ ■ ■

Digital IZ1492 IZ1493

■

1-Phase 3-Phase

■ ■

Less than 35 microampere LIM hazard current. No interference with medical equipment. Hybrid design with special phaselocking circuitry for ultimate stability and repeatability. Voltage-free SPDT contact for external usage. LIM overload protection with automatic reset. Field adjustable 2 or 5 mA response value. Easy-to-clean rugged Lexan front. Analog display IZ1490 and IZ1491. Digital display IZ1492 and IZ1493.

Product Description The Line Isolation Monitor (LIM) detects the total leakage impedance to ground in an AC isolated or ungrounded power system. Based on this information, the maximum Total Hazard Current (THC) is determined. Analog IZ1490 IZ1491

1-Phase 3-Phase

7 (177.8)

4-7/16 -7/16 (112.7) 12.7

4 (10 01..6) View from Back 4-1/4 4 (108.0 (108.0)

6 1/8 6-1/8 (155.6) (155 6) 6-1/8 (155.6)

1/8 / (3.2) 3.2)

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Recessed Molex Connector

The LIM is available for operation in 50 or 60 Hz systems with the following AC voltages: 24, 100, 110, 120, 200, 208, 220, 230, 240 and 277V. The LIM requires a separate supply voltage of 120V AC when used with a system voltage 24V. Otherwise, the supply voltage for the LIM is taken from the system to be monitored. Two separate ground connections are provided for added safety when wiring the LIM into an Isolated Power System. Each ground should be wired individually to the Reference Grounding Bus. A break in either connection will cause the LIM to alarm.

The THC is displayed either on an analog or digital panel meter. Normally, the green LED is “on” and the meter is in the non-alarm or safe green zone. THC levels will increase as additional loads are connected to the system and/or when a line-to-ground fault has suddenly occurred or is slowly developing. There is a visual and audible alarm when the THC exceeds the LIM setting of either 2 or 5 mA. Relay output contacts are also available which can be wired into a circuit to trigger an external alarm. The visual alarm remains on for the duration of the fault. The buzzer can, however, be muted at the discretion of personnel in the vicinity of the LIM. The red LED that is built into the mute switch comes “on” to indicate a muted condition. A test switch can be activated to checkout the LIM operation. This action creates the equivalent of a fault and causes the LIM to react as if a true fault had occurred in the system. The meter then goes into the red alarm zone, the green LED goes off, the red LED comes on and the buzzer sounds. The operation of this switch does not add to the risk of electric shock within the system in actual use, nor does it include the effect of the line-to-ground stray impedance of the system. The LIM has provisions for connecting one or more remote stations with or without meter. Similar information and test action is available at these remotes as is provided by the LIM.

Operational Information 2-1/2 2 (63.5) (63.5

The LIM function is to calculate and display the true maximum value of the Total Hazard Current (THC). The LIM accomplishes this task using a patented technique of measurement.

Figure 36.0-19. Line Isolation Monitors — Dimensions in Inches (mm)


CA08104001E

January 2003

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36.0-11

Ref. No. 1323

Technical Data Physical Details

Table 36.0-10. Technical Data for LIM Rated Insulation Voltage

300V

Insulation Class in Accordance with UL 1022 Dielectric Voltage-Withstand Test

1500V

Rated Service Rating

Continuous Operating

Rated Mains Voltage of VN Frequency Range of VN Operating Range of VN Maximum Power Consumption

24/100/110/120/200/208/220/230/240V AC, Single-Phase 50 or 60 Hz (+/- 1%) 85% – 110% of Rated Voltage 7.5 VA

Measuring Current Monitor Hazard Current

Maximum 18 µA Maximum 35 µA

Minimum Internal Impedance at 50/60 Hz

4MΩ

Nominal Response Value Response Tolerance Response Retardation Response Hysteresis

5 mA Changeable to 2 mA 1.8 to 2 mA or 4.6 to 5 mA < 5 sec. 15% of Response Value

Output Contact Assemblies

One Voltage-Free SPDT Contact and one 12V AC, 120 mA Remote Indicator Contact 250V 6A

Rated Contact Voltage Make Capacity Break Capacity at 250V DC and L/R = 0 at 60V DC and L/R = 0 at 24V DC and L/R = 0 Switching Life (220V AC/60 Hz)

0.4A 0.7A 6A 2 x 106 Cycles

Operation Mode

Continuous

LIM Overload Protection

Built-in Thermal Overload with Automatic Reset

Ambient Temperature When Operating When Stored

The LIM is less than 2-1/2 inches (63.5 mm) deep. Cutout required for panel mounting is 4-5/16 x 6-3/16 (+0, -1/32) inches (109.6 x 157.2 mm). Mounting holes are on 4-inch (101.6 mm) and 6-1/2-inch (165.1 mm) centers. A 15-pin female Molex connector is built into the side of the LIM. A terminal board assembly with cable and 15-pin male Molex connector is available to facilitate field wiring. A buzzer sound level adjustment, using a 1/8-inch (3.2 mm) Allen head wrench is conveniently accessible through a hole in the top-side of the LIM. The housing must be opened to change the LIM response value to either 2 or 5 mA.

10°C – 50°C 50°F – 122°F -20°C – 50°C 10°F – 122°F

Mounting Orientation

Any

Connector

15-pin Molex, Type 03-09-2152

Weight

Approximately 1.75 Lbs (.8 kg)

36

CA08104001E


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CSA is a registered trademark of the Canadian Standards Association. UL is a federally registered trademark of Underwriters Laboratories Inc. National Electrical Code and NEC are registered trademarks of the National Fire Protection Association, Quincy, Mass.

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CA08104001E

Contents Hospital Isolation Equipment - Eaton

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