Installation Manual
ASCO 3ATS, 3ADTS, 3NTS, 3NDTS
381333-406
ASCO Power Technologies
Page 5
Figure 7. Transfer button and indicator lights.
3 – Electrical Operation
This procedure will check the electrical operation of the
transfer switch.
Close the transfer switch enclosure door and
tighten the screws before you test electrical
operation.
Perform steps 1 through 5 at the right. Observe the status
lights. See Figure 7.
●
Black circle means light is on.
○
White circle means light is off.
NOTE:
For 3NTS manually start the emergency generator at
the generator. Then press the transfer button for load transfer.
If the inphase transfer feature is activated, transfer may not
occur immediately. Transfer will occur when the phase
relationship between sources is correct. Press the transfer
button again for load retransfer to normal, then manually stop
the generator at the generator.
Also see User’s Guide 381333-400 for inphase transfer and
time delay settings in the controller.
This completes the functional test of the transfer switch.
Leave the engine-generator starting control in the automatic
position.
The normal source must be available and the generator
must be ready to start. Check that the normal source
accepted light is on.
1
For 3ATS & 3ADTS press the transfer
button. The engine should start and run
within 15 seconds. For 3NTS & 3NDTS
the generator must be started manually
at the generator.
The emergency source accepted light should come on.
2
For 3ATS & 3ADTS the transfer switch should transfer to
the emergency position. The load on emergency light
should come on and the load on normal light should go
off. For 3NTS & 3NDTS press the transfer button for
load transfer. For 3ADTS & 3NDTS both lights will be off
during the delayed-transition transfer time delay.
If the transfer to emergency delay is
used, the transfer occurs after a time
delay. For immediate transfer (bypass
timer) press the transfer button again.
3
For 3ATS & 3ADTS the transfer switch should transfer
back to the normal position. The load on normal light
should come on and the load on emergency light should
go off. For 3NTS & 3NDTS press the transfer button for
load retransfer. For 3ADTS & 3NDTS both lights will be
off during the delayed-transition transfer time delay.
If the retransfer to normal delay is used
the retransfer should occur after a time
delay. For immediate retransfer (bypass
timer) press the transfer button again.
4
For 3ATS & 3ADTS the unloaded running delay keeps
the generator running for a cool-down period. Then the
generator should stop and the emergency source
accepted light should go off. For 3NTS & 3NDTS
manually stop the generator at the generator (after a
cool-down period).
5
WARNING
!
Observe
these
lights
Press this
button
