Operator's Manual

Operator’s Manual ASCO 336 / 337
381333-427 A ASCO Power Technologies Page 7
Figure 5. Buttons and indicator lights on generator controller for voltage checks.
2 – Voltage Checks
First check the nameplate on the PCS 336 System and the
transfer switch; the rated voltage must be the same as
Generator 1 & 2 rated output voltages. Be sure that these
controls are the following positions before starting:
 Master Control Switch in Off position
 Power Management Selector switch in Off position
 Generator 1 Circuit Breaker closed (on)
 Generator 2 Circuit Breaker closed (on)
 Both Generators off, not running
 Transfer switch contacts open (both upper & lower)
Use extreme caution when using a meter to
measure voltages in the following steps.
Do not touch power terminals; shock, burns,
or death could result!
Multiple sources of potentially lethal voltages
may be present in any one enclosure!
Perform steps 1 through 6 at the right. Observe the indicator
lights. See Figure 5.
* If necessary, adjust the voltage regulator on the generator
according to the manufacturer’s recommendations. The PCS
336 System will respond only to the rated voltage specified on
the transfer switch nameplate.
Also see the controller manual for settings.
1
Press the MAN (manual)
button on both controllers.
2
Press the start button for
Generator 1. The generator
running light and generator
acceptable light should both
come on.
Gen 1 Acceptable
3
Press the start button for
Generator 2. The Generator 2
acceptable light should come
on.
Gen 2 Acceptable
4
Use an accurate voltmeter to
check phase to phase and
phase to neutral voltages
present at the transfer switch
Generator 1 & 2 terminals.*
5
Use a phase rotation meter to
check phase rotation of
Generator 1 & 2 at the
transfer switch. They must
be the same.
6
Shut down Generator 1 & 2 by
pressing both stop buttons.
The Generator 1 & 2 accepted
lights should go off. Then put
starting controls (on generator
sets) in the automatic position.
Gen 1 and Gen 2
Continue to 3 – Electrical Operation on the next page.
DANGER
!
Start button
Stop button
Generator running light
Generator voltage and frequency acceptable light
DANGER
!
MAN (manual) button