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TESTING & SERVICE
(continued)
2--2
TROUBLE- SHOOTING
Note any optional a ccessories that may be furnished on
the 7ADTB and review their operation. Refer to any
separate drawingsand/orinstructionsthat 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
ofthebypassswitchortransferswitch!
Table B. Trouble-Shooting Checks.
P
R
O
B
L
E
M
CHECK IN NUMERICAL SEQUENCE
P
R
O
B
L
E
M
1OPERATION 2 GEN-SET 3VOLTAGE
Engine–generator set does
not start when the Transfer
Control sw itc h 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
Feature1Ctimedelayplus
engine cranking and star ting.
Starting control must be in the
automatic position. Batteries
must be charged and
connec ted. Check wiring to
engine starting contacts.
---
Transfer switch does not
transfer the load to the
emergency source after the
engine–generator set starts.
W ait for Feature 2B time delay
to time out.
Generator output cir cuit
breaker must be closed.
Generator frequency must be
at least 95% of nominal (57 Hz
for a 60 Hz system.) *
Voltmeter should r ead at least
90% of nominal phase to
phase voltage between
terminals EA and EC (or EL1
and EL2 for 2 po le switches)*
Transfer switch does not
transfer the load to normal
source when normal returns
or when the Transfer Control
switch is released.
W ait for Feature 3A time delay
to time out.
---
Voltmeter should r ead 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 po le switches) .
Gen. does not stop after load
retransfer to normal source.
W ait for Feature 2E time delay
to time out.
Starting control must be in the
automatic position.
---
Load Disconnect Active light
comes on.
W ait for l o ad disconnec t time
delay to time out.
Explanation: Transfer switchin delayed t ransition transfermode.
Load disconnect time delay is adjustablefrom 0to 5min. 59sec.
Load Disconnect Active light
staysonlongerthan6min.
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 orASI: in the United States, call1–800–800–2726 orin Canada call 1–888–234–2726. Furnish the Serial No.,
Catalog No., and Bill of Material (BOM) No. from the t ransfer switch nameplate.
MAINTENANCE H AND LE
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. By pass, isolate, and withdraw the transfer switch
(pages3–1 through 3–4).Then locateand removethe
maintenance handle from the clip (inside lower lef t
side). Insert the handle onto the shaft onthe 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.