
SECTION 2 TESTING & SERVICE
2--1
TRANSFER TEST
Test the Automatic Transfer Switch portion of the 7000
Series 7ATB at least once a month. This procedure
checks the electrical operation of the Transfer Switch
and Controller. Put the engine–generator starting con-
trol (at the engine–generator set) 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, un-
less the the Transfer Switch contacts are bypassed before
the test. See pages 3–1 through 3–4 for bypassing & iso-
lating 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
Tes t procedure on page 1–4.
PREVENTIVE MAINTENANCE
Reasonable care in preventive maintenance will insure
high reliability and long life for the 7000 Series 7ATB.
An annual preventive maintenance program is recom-
mended.
ASCO Services, Inc. is ASCO Power Technologies’s
national service organization. In the US ASI can be
contacted at 1-800-800-2726 for information on pre-
ventive 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!
Clean the 7ATB enclosure.
Brush and vacuum away any excessive dust accu-
mulation. Remove any moisture with a clean cloth.
Check the transfer switch contacts.
Bypass, isolate, and withdraw the transfer switch.
Then remove the transfer switch interphase barri-
ers and check the condition of the contacts. Re-
place contacts when pitted or worn excessively. Re-
install the interphase barriers carefully, page 3–4.
Maintain 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 920799.
Check all cable connections & retighten them.
REPLACEMENT PARTS
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 Technolo-
gies Sales Office or ASI:
In the United States
call 1 – 800 – 800 – ASCO ( 2726 )
DISCONNECTING THE CONTROLLER
The harness disconnect plugs are furnished for repair
purposes only and should not have to be unplugged.
If the controller must be isolated, follow these steps:
Bypass–Isolation Switch 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 squeez-
ing 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 page 3–5.
MANUAL LOAD TRANSFER
This procedure manually transfers load to other source if
the Transfer Switch or Controller are out of service.
Close enclosure doors to prevent personal
injury in case of electrical system fault.
1. Bypass the connected ATB source. Turn Bypass Han-
dle to EMERGENCY or NORMAL (see page 3–2).
2. Isolate to Test. Turn the Isolation Handle to TEST
position (see page 3–3).
3. Turn the Bypass Handle to OPEN, then to the other
source (see page 3–1). The load will be interrupted.
4. Turn the Isolation Handle clockwise to the CONN
[connected] position (see page 3–4).