499.89 Kb



7000 Series ATB

Automatic Transfer &


F–design,3000 and 4000 amp. sizes


section-pageINSTALLATION . . . . . . . . . . . . . . . . . . . . . . . .1-1Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1Power Connections . . . . . . . . . . . . . . . . . . . .1-2Engine Starting & Auxiliary Circuits . . . . . .1-2Functional Test . . . . . . . . . . . . . . . .1-5,1-6,1–7

TESTING & SERVICE . . . . . . . . . . . . . . . . . . 2-1Transfer Test . . . . . . . . . . . . . . . . . . . . . . . . . .2-1Preventive Maintenance . . . . . . . . . . . . . . . .2-1Disconnecting the Controller . . . . . . . . . . . .2-1Manual Load Transfer . . . . . . . . . . . . . . . . . .2-2Trouble-Shooting . . . . . . . . . . . . . . . . . . . . . .2-2

BYPASSING & ISOLATING . . . . . . . . . . . . . . 3-1Bypassing the ATS . . . . . . . . . . . . . . . . . . . .3-1Isolating the ATS . . . . . . . . . . . . . . . . . . . . . .3-1Return to Service . . . . . . . . . . . . . . . . . . . . . .3-3

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . back cover

An experienced licensed electrician must install ATB

Refer to the outline and wiring drawings provided with your 7000 Series ATB for all installation and connection details and accessories.

Refer to Group 5 Controller User’s Guide381333–126 for ATS status display messages, time delays, pickup & dropout settings, and adjustments.

Rating Label

Each 7000 Series ATB contains a rating label to define the loads and fault circuit withstand/closing ratings. Refer to the label on the Transfer Switch for specific values.


Do not exceed the values on the rating label. Exceeding the rating can cause personal injury or serious equipment damage.


The Transfer Switch nameplate includes data for each specific 7000 Series ATB. Use the switch only within the limits shown on this nameplate. A typical Catalog Number is shown below with its elements explained:

Catalog Number Identification

Typical 7000 Series ATB catalog no. for overlapping neutral, 3 pole, 4000 amp, 480 V, in Type 1 enclosure:

7ATB C 3 4000 N 5 C



Phase Poles










A – solid


2 – single Ø




A 115

J 400



5 – standard


C – type 1

C – overlapping


3 – three Ø




B 120

K 415



5X – if accesso-


F – type 3R

blank ---none






C 208

L 440



ries ordered


G – type 4
















D 220

M 460





L – type 12







E 230

N 480





blank – open type







F 240

P 550























G 277

Q 575












H 380

R 600
















50 Hanover Road, Florham Park, New Jersey 07932–1591USA




1 800 937–2726(ASCO), for service call 1 800800–2726(ASCO)

ASCO POWER TECHNOLOGIES CANADA PO Box 1238, 17 Airport Road, Brantford, Ontario, Canada N3T 5T3 telephone 519 758–8450,fax 519758–0876,for service call 1 888234–2726(ASCO)


The ASCO 7000 Series Automatic Transfer & Bypass– Isolation Switch (ATB) consists of an upper bypass–isola-tion switch, a transfer switch, a monitoring and transfer controller, anddoor–mountedcontrols. The ATB is factory wired and tested. Installation requires removal of the shipping skid then securing the enclosure to the supporting foundation.

Remove the Transfer Switch

The Transfer Switch is shipped inside the enclosure (ATS side) in the fully engaged position. Before installing the enclosure remove the Transfer Switch as follows:

1.Open the enclosure doors and install the two ramps (stored on right side).

2.Remove the Isolation Handle which is stored on the lower right front of the Transfer Switch carriage frame. Install the Isolation Handle onto the protruding shaft and turn it counterclockwise (approximately 10 turns) until it stops.

3.Unplug J2 and J5 harness plugs, and roll out the Transfer Switch. Cover it to keep it clean.

Supporting Foundation

The supporting foundation and adjacent area must be level and straight, otherwise the Transfer Switch and enclosure may not align causing door problems. The floor under the enclosure must be flat and level. This is very important! The structure of the enclosure must be straight and square. Allow at least 36 inches for roll out of Transfer Switch. Refer to the enclosure drawing for required door opening space.

If bottom cable entry is used, the foundation must be prepared so that conduit stubs are located correctly. Refer to appropriate enclosure outline drawing for specified cable entrance area and location. Provide cable bending space and clearance to live metal parts. When a concrete floor is poured, use interlocking conduit spacer caps or a wood or metal template to maintain proper conduit alignment.


Refer to the enclosure outline drawing furnished with this switch and mount the 7000 Series ATB according to the details and instructions shown on the drawing.

Bolt the cubicle sections together so that they are lined up on the front faces. See Figure 1–1.

De–energizethe conductors before making any line or auxiliary circuitry connections. Be sure that Normal and Emergency line connections are in proper phase rotation. Place engine generator starting control in the OFF position. Make sure engine generator is not in operation.

Testing Power Conductors

Do not connect the power conductors to the ATB until they are tested. Installing power cables in conduit, cable troughs, and ceiling-suspendedhangers often requires considerable force. The pulling of cables can damage insulation and stretch or break the conductor’s strands. For this reason, after the cables are pulled into position, and before they are connected they should be tested to verify that they are not defective or have been damaged during installation.


Protect the switch from construction grit and metal chips to prevent malfunction or shortened life for the ATB switch.


INSTALLATION (continued)

Connecting Power Conductors

A Wiring Diagram is furnished with the ATB. All wiring must be made in accordance with the local codes. After the power cables have been tested, connect them to the appropriate terminal lugs on the Bypass Switch as shown on the wiring diagram provided with this ATB. Make sure that the lugs provided are suitable for use with the cables being installed. Standard terminal lugs are solderless screw type and will accept the wire sizes listed on the drawings provided with the ATB. Be careful when stripping insulation from conductors; avoid nicking or ringing the conductor. Remove surface oxides from conductors by cleaning with a wire brush. Follow conductor manufacturer’s instructions when aluminum conductor is used. Apply joint compound to conductor, then carefully wipe away excess compound. Tighten the cable lugs to the torque specified on the rating label.


Be sure that the Normal and Emergency power connections are in proper phase rotation.

Figure 1–1.Bus tie plates (top view).


See job specific drawings supplied with ATB.

Bus Connections

If bus connection is used, use SAE grade 5 hardware to connect bus to appropriate terminal plates on bypass switching device. Wipe off bus surfaces before they are joined. If bus is dirty, gently clean surfaces with a non-flammablesolvent. Avoid touching cleaned surfaces.


Do not breathe cleaning solvent vapors.

Use SAE grade 5 hardware and tighten the bolted joints to the torque specified in Table 2-1.


The reliability of the connection depends on how clean and how tight the joint is.

Table 2-1.Tightening torque values for bolted joints.

Bolt Diameter


(Grade 5 hardware)

Tightening Torque

in inches

in foot pounds












All internal connections are made at the factory. The bypass switch, transfer switch, and control panel are joined together by an interconnecting wire harness. The disconnect plugs are already engaged on enclosed switches. For open–typeswitches, the plugs must be engaged after installation is completed. Align harness plugs with sockets in the control and push them together until they are secure.

Engine Starting Contacts

and Auxiliary Circuits

The engine control contact signal connections and auxiliary circuits are located on terminal block TB as shown on the Wiring Diagram provided with the ATB. Connect the signal wires to the appropriate terminals.


INSTALLATION (continued)

Install the Transfer Switch

After the enclosure is installed and power cables or bus connected to the Bypass Switch, the Transfer Switch carriage can be rolled in. The floor of the cabinet must be free of debris and clean. If necessary, use a vacuum cleaner. Make a thorough inspection to be sure no tools are left inside. The Bypass Handle must be in the BYPASS POS position (closed on normal). The Isolation Handle (drawout crank) must be fully counterclockwise against stop.

Do not apply any electrical power to the ATB yet.

It is not necessary to remove the barriers from the bypass switch and transfer switch. If you do remove them, however, reinstall them carefully.

NOTE: Be sure to roll the correct Transfer Switch into the enclosure. If more than one is supplied, each will be labeled above the solenoid operator.

The Transfer Switch NORMAL contacts must be closed. If not, use the manual operator handle (maintenance handle stored on lower carriage) to manually operate the switch. See Figure1–10.Check that all arc chutes and interphase barriers are in place on the Transfer Switch. Then grasp the Transfer Switch carriage frame and roll it into the cabinet (isolation contacts facing inward). Align the rollers between the floor guides and push the carriage in until its crank pins engage the latch plates on both sides. Then follow the procedure below:

NOTE: Solenoid lockSL1 on the Isolation shaft inhibits operation of the drawout (Isolation contacts) unless the Transfer Switch and Bypass Switch are in compatible positions. This solenoid must energize to unlock. Because all power sources arede-energized,the interference tag defeats the solenoid in the following inspections.

Do the three inspections on page 1-4without any electrical power connected. The inspections will verify that the isolation contacts are in proper alignment. If necessary, add shims under the floor. It may be helpful to remove the the right side of the enclosure to expose the isolation contacts during the inspections.


Do not apply any power to the Bypass Switch. Be sure that the Normal and Emergency source circuit breakers are OPEN before proceeding.

Remove interference tag after making inspection

on page 1-4.SL1 solenoid






Handle shaft

Figure1–2.Solenoid latch interference tag.

Turn the draw-outcrank while checking alignment of the isolation contacts.

Figure 1–3.Isolation Handle.

Transfer Switch


Figure 1–4.Switched neutral interlock.


INSTALLATION (continued)

Inspection 1


Do not force the Isolation Handle. Be sure that the sensing lead isolation contacts do not hit the male stabs head on, but rather slide on them.


Figure 1–5.Isolation contacts in TEST position.




(without electrical power)




Turn the Isolation Handle (Figure 1–3)clockwise approximately 7 or 8 turns.


The Transfer Switch should be pulled inward; the sensing lead isolation

contacts should make with the male stabs as shown in Figure 1–5.



Inspection 2


Do not force the Isolation Handle. Be sure that the isolation contact fingers make with the male stabs on both sides in the CONNECTED position.


Figure 1–6.Isolation contacts CONNECTED (CLOSED).

Move ATS From TEST To CONNECTED Position

(without electrical power)

With solenoid latch interference tag in place (Figure 1–2),continue slowly Action turning the Isolation Handle clockwise until it stops (approximately 6 or 7

turns). Now remove the interference tag from the solenoid latch.

The Transfer Switch should be pulled inward; the isolation contact fingers Observe should make with the male stabs as shown in Figure 1–6.Also check that

the Bypass Switch switched neutral contacts have opened (Figure 1–4).

Inspection 3


Be sure that the isolation contacts disconnect in the TEST position; the sensing lead contacts should still touch the male stabs.


Figure 1–7.Isolation contacts back in TEST position.


Move ATS From CONNECTED Back To TEST Position


(without electrical power)




Turn the Isolation Handle (Figure 1–3)back counterclockwise until the

isolation contacts separate (approximately 6 or 7 turns).



The Transfer Switch should be pushed outward; the isolation contacts


should disconnect, but the sensing lead contacts should remain touching


as shown in Figure 1–7.

If all inspections are satisfactory connect harness plugs J2 and J5. Proceed to the Function Test.


INSTALLATION (continued)

observe these lights

Automatic Transfer

& Bypass–IsolationSwitch




Transfer Switch

Transfer Switch


































Figure 1-8.Standard controls and indicators.

Functional Test

Read all instructions on the Wiring Diagrams and labels affixed to the ATB. Note the control features that are provided and review their operation before proceeding.

After installing the ATB check the following:

S Bypass Handle should be in theBYPASS POS position (closed on normal)

S Isolation contacts should be in theTEST position (see pages1-3and1-4).

S Automatic Transfer Switch should be in theN (normal) position

If handles are not in correct positions, follow instructions for Bypassing and Isolating the automatic transfer switch in Section 3.Do not force the handles. Electrical interlocks prevent a wrong sequence of operation.

1 – Voltage Checks

First check nameplate on transfer switch; rated voltage must be the same as normal and emergency line voltages.

Use extreme caution when using a meter to measure voltages. Do not touch power terminals; shock, burns, or death could result !

Perform steps 1–6at the right. Observe the status lights. See Figures1–8and1–11.

Black square means light is on.

White square means light is off.

*If necessary, adjust voltage regulator on generator per the manufacturer’s recommendations. The ATB will respond only to rated voltage specified on the nameplate.

Now continue to 2 – Manual Operation Test, next page.

Close the normal source circuit breaker. The Transfer Switch

1Connected To Normal and the Normal Source Acceptedlights should come on.

Use an accurate voltmeter to check phase to phase and

2phase to neutral voltages present at the transfer switch normal source terminals.

Close the emergency source circuit breaker. (Start generator,

3if necessary.) The Transfer Switch Connected To Normal &Emergency Source Accepted lights should come on.

Use an accurate voltmeter to check phase to phase and

4phase to neutral voltages present at the transfer switch emergency source terminals.*


Use a phase rotation meter to 5 check phase rotation of emer-

gency source; it must be the same as the normal source.

Shut down the engine–genera-tor, if applicable. TheEmergency Source Accepted light should

6go off. Then put the starting

control selector switch (on the generator set) in the automatic position. Close enclosure door.


INSTALLATION (continued)

2 – Manual Operation Test

This procedure will check the manual operation of the Bypass Switch, Isolation Switch, and Transfer Switch. Observe the lights on the Status Indicator panel. The Bypass Switch CLOSED ON NORMAL and theTEST lights should be on. See Figure1–11.

1.Isolate the Automatic Transfer Switch:

Install the Isolation Handle and turn it counterclockwise until it stops (approximately 7 or 8 turns). The Automatic Transfer Switch is now in the Disconnected position (See Figure1–9.).

The DISCONNECTED light should come on.

Turn draw-outcrank counterclockwise approximately 7 or 8 turns until it stops.

Figure 1–9.Open (disconnect) isolation contacts.

2.A detachable manual operator handle is provided on the Transfer Switch for maintenance purposes only.


Do not manually operate the Transfer Switch unless the Isolation Handle is in the OPEN position and theDISCONNECTED light is on.

Figure 1–10.Transfer Switch manual operator handle.


Figure 1–11.Status Indicator Panel.

Insert the manual handle into the hole in the rotating weight as shown in Figure 1–10.Move the installed handle up and down to manually operate the Transfer Switch. The Switch should operate smoothly without binding. Return the Transfer Switch to theNORMAL position. Remove manual operator handle and store it on the Transfer Switch in the place provided. Now go to page1–7.

Turn draw-outcrank clockwise approximately 7 or 8

turns until TEST light comes on.

Figure 1–12.Move ATS toTEST position.

observe these lights

INSTALLATION (continued)




Automatic Transfer




& Bypass–IsolationSwitch




Transfer Switch

Transfer Switch





















this switch

















Figure 1-13.Standard controls and indicators.

3 – Electrical Operation

This procedure checks electrical operation of the ATS.


Be sure to close all enclosure doors before proceeding to prevent personal injury in case of electrical system fault.

Transfer Test

The ATS should still be bypassed and isolated. Both normal and emergency sources must be available and the emergency source generator (if used) must be capable of being started; put engine starting control in automatic position. TheTransfer Switch Connected to Normal light and theNormal Source Accepted light should be on.

1.Turn Isolation Handle clockwise about7–8turns untilTEST light comes on,DISCONNECTED light off.

2.Perform steps 1–5at right. Observe the status lights.

Black square means light is on.

White square means light is off.

3.Turn the Isolation Handle clockwiseuntil it stops (about 6 or 7 turns). TheCONNECTED light should come on,TEST light off. Remove the Isolation Handle and store it inside the enclosure on the carriage frame on the right side.

4.Turn the Bypass Handle clockwise to theAUTOMATIC POS position. The Bypass SwitchCLOSED ON NORMAL light should go off.

This completes the Functional Test of the ATB. The generator’s starting control should be left in automatic position.

The Transfer Switch Connected

1to Normal and Normal Source Acceptedlights should be on.

Turn and hold Transfer Controlswitch clockwise to Transfer

2Test until the engine starts and runs (within 15 sec.). The

Emergency Source Accepted light should come on.

Transfer switch will operate to the Emergency position after Feature 2B time delay. The

3Transfer Switch Connected To Emergency light should come on and Load Connected to Normallight goes off.

Transfer switch will operate back to Normal position after Feature 3A time delay. For immediate retransfer turn Transfer

4Control counterclockwise to

Retransfer Delay Bypass. The Transfer Switch Connected To Normallight should come on;

Transfer Switch Connected to Emergency light should go off.

The engine–generatorwill stop after the Feature 2E time delay

5(unloaded running engine cooldown). The Emergency Source Accepted light should go off.




Test the Automatic Transfer Switch portion of the 7000 Series ATB at least once a month. This procedure checks the electrical operation of the Transfer Switch and Controller. Put the engine–generatorstarting control (at theengine–generatorset) in automatic mode.

In the following test the generator will start, the load will be transferred to the Emergency source, then back to the Normal source. An interruption to the load will occur, unless the the Transfer Switch contacts are bypassed before the test. See page 3–1for bypassing & isolating instructions if no interruption of load is required.


Be sure to close the enclosure door before proceeding to prevent personal injury in case of electrical system fault.

Perform the five–step Electrical Operation---Transfer Testprocedure on page 1–7.


Reasonable care in preventive maintenance will insure high reliability and long life for the 7000 Series ATB. An annual preventive maintenance program is recommended.

ASCO Services, Inc. (ASI) is ASCO Power Technologies’s national service organization. ASI can be contacted at 1-800-800-2726(ASCO) for information on preventive maintenance agreements.

Checklist for Yearly Inspection

Hazardous voltage capable of causing shock, burns, or death is used in this switch.

Deenergize both Normal --Emergency power sources before performing inspections!

jClean the ATS enclosure. Brush and vacuum away any excessive dust accumulation. Remove any moisture with a clean cloth.

j Check the transfer switch contacts. Remove transfer switch barriers and check the condition of the contacts. Replace contacts when pitted or worn excessively. Reinstall the barriers carefully.

jMaintain transfer switch lubrication. If switch is subjected to severe dust or abnormal operating conditions, renew factory lubrication on all movements and linkages. Relubricate solenoid operator if TS coil is replaced. Don’t use oil; order lubrication kit 75-100.

j Check all cable connections & retighten them.


Replacement parts are available in kit form. When ordering parts provide the Serial No., Bill of Material No. (BOM), and Catalog No. from the transfer switch nameplate. Contact your local ASCO Power Technolgies sales office or ASI.

In the United States call 1--800--800--ASCO(2726) In Canada call1--888--234--ASCO(2726)


The harness disconnect plugs are furnished for repair purposes only and should not have to be unplugged. If the control panel must be isolated, follow these steps:

Bypass--IsolationSwitch is energized! Do not touch isolation contact fingers; shock, burns, or death could result!

Disconnecting the Plugs

1.Bypass and Isolate the Automatic Transfer Switch.

2.Open the upper enclosure door.

3.Separate the two quick disconnect plugs by squeezing the latches. Do not pull on the harness wires.

Reconnecting the Plugs

1.The ATS should be still bypassed and isolated.

2.The two harness plugs and sockets are keyed. Carefully align the plugs with the sockets and press straight in until the latches click.

3.Close the enclosure doors.

4.Follow Return to Service instructions on page3–3.


TESTING & SERVICE (continued)


Note any optional accessories that may be furnished on the ATB and review their operation. Refer to any separate drawings and/or instructions that may be packed with the ATB.

Hazardous voltage capable of causing shock, burns, or death is used in this switch.

Do not touch the power or load terminals of the transfer switch!

Table 2-1.Trouble-ShootingChecks.














Engine–generatorset does

Hold Transfer Test switch 15

Starting control must be in the


not start when the Transfer

seconds or the outage must

automatic position. Batteries


Control switch is turned and

be long enough to allow for

must be charged and


held in Transfer Testposition

Feature 1C time delay plus

connected. Check wiring to


or when normal source fails.

engine cranking and starting.

engine starting contacts.






Transfer switch does not

Wait for Feature 2B time delay

Generator output circuit

Voltmeter should read at

transfer the load to the

to time out.

breaker must be closed.

least 90% of nominal phase to

emergency source after the


Generator frequency must be

phase voltage between

engine–generatorset starts.


at least 95% of nominal (57

transfer switch terminals EA &



Hz for a 60 Hz system.) *

EC (or EL1 & EL2 for 2 pole)*





Transfer switch does not

Wait for Feature 3A time delay


Voltmeter should read at least

transfer the load to normal

to time out.


90% of nominal phase to

source when normal returns



phase voltage between

or when the Transfer Control


transfer switch terminals NB &



switch is released.



NC, NC & NA, & NA & NB (or




NL1 & NL2 for 2 pole).






Wait for Feature 2E time delay

Starting control must be in the


not stop after load retransfer

to time out.

automatic position.


to the normal source.








* These are factory settings. Refer to Controller User’s Guide.

If the problem is isolated to circuits on the controller or the transfer switch, call your local ASCO Power Technologies sales office or ASI. In the United States, call 1–800–800–2726.In Canada, call1–888–234–2726.Furnish the Serial No., Bill of Material (BOM) No., and Catalog No. from the transfer switch nameplate.


This procedure manually transfers load to other source if the Transfer Switch or Control Panel are out of service.



Close all enclosure doors to prevent personal


injury in case of electrical system fault.


1. Be sure that the Bypass Handle is in the BYPASS

Figure 2–1.Bypass Handle.

POS (position) (see page3–1).

2.Be sure that the Isolation Handle is in the TEST orDISCONNECTED position (see page3–2).

3.Turn the Bypass Handle clockwise to AUTOMATIC POS (position).

4.Then pull–outorpush–inthe Bypass Handle and turn it back to BYPASS POS (select opposite source):

-Emergency Source - pull out the handle

-Normal Source - push in the handle