TESTING & SERVICE
(continued)
2--2
TROUBLE-SHOOTING
Note any optional accessories that may be furnished on
the 7ADTB and review their operation. Refer to any
separate drawings and/or instructions that may be packed
with the 7ADTB. See Table B.
Hazardous voltage capable of causing shock,
burns, or death is used in this switch.
Do not touch the power or load terminals
of the bypass switch or transfer switch!
Table B. Trouble-Shooting Checks.
PROBLEM
CHECK IN NUMERICAL SEQUENCE
PROBLEM
1 OPERATION
2 GEN-SET
3 VOLTAGE
Engine–generator set does
not start when the
Transfer
Control
switch is turned and
held in
Transfer Test
position
or when normal source fails.
Hold
Transfer Test
switch 15
seconds or the outage must
be long enough to allow for
Feature 1C time delay plus
engine cranking and starting
.
Starting control must be in the
automatic position. Batteries
must be charged and
connected. Check wiring to
engine starting contacts.
---
Transfer switch does not
transfer the load to the
emergency source after the
engine–generator set starts.
Wait for Feature 2B time delay
to time out.
Generator output circuit
breaker must be closed.
Generator frequency must be
at least 95% of nominal (57 Hz
for a 60 Hz system.) *
Voltmeter should read at least
90% of nominal phase to
phase voltage between
terminals EA and EC (or EL1
and EL2 for 2 pole switches)*
Transfer switch does not
transfer the load to normal
source when normal returns
or when the
Transfer Control
switch is released.
Wait for Feature 3A time delay
to time out.
---
Voltmeter should read at least
90% of nominal phase to
phase voltage between
terminals NB and NC, NC and
NA, and NA and NB (or NL1
and NL2 for 2 pole switches).
Gen. does not stop after load
retransfer to normal source.
Wait for Feature 2E time delay
to time out.
Starting control must be in the
automatic position.
---
Load Disconnect Active
light
comes on.
Wait for load disconnect time
delay to time out.
Explanation: Transfer switch in delayed transition transfer mode.
Load disconnect time delay is adjustable from 0 to 5 min. 59 sec.
Load Disconnect Active
light
stays on longer than 6 min.
Check load disconnect time
delay setting. Call ASI.
Explanation: Transfer switch contacts are open longer than 5
min. 59 sec (maximum setting). Load remains disconnected.
* These are factory settings. Refer to
Controller’s 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 or in Canada call 1–888–234–2726. Furnish the Serial No.,
Catalog No., and Bill of Material (BOM) No. from the transfer switch nameplate.
MAINTENANCE HANDLE
Bypass and isolate the Transfer Switch before
using the maintenance handle! See pages
3–1 through 3–4. Remove the maintenance
handle after using it; store it inside.
1. Bypass, isolate, and withdraw the transfer switch
(pages 3–1 through 3–4). Then locate and remove the
maintenance handle from the clip (inside lower left
side). Insert the handle onto the shaft on the left side
of the operator of the transfer switch See Figures
2–1, 2–2, 2–3 and Table C.
2. Move the maintenance handle up or down as shown
to manually operate the transfer switch. Operate
both upper and lower contact shafts. Observe the
window indicators (right side). Remove the mainte-
nance handle and store it on the lower left side.
window
indicators
O
is open
C
is closed
contact
position
indicators
(right side)
Emergency contacts
(upper shaft)
Normal contacts
(lower shaft)
Figure 2–1. Contact position indicators.
