Installation (cont’d)
DANGER 
HAZARDOUS VOLTAGE
(Can Cause Severe Injury or Death)
Turn OFF all power before installation, adjustment, or removal of transfer switch or any of its components.
Functional Test
Functional testing of the automatic transfer switch (ATS) is described in this section. Before proceeding, read and understand all instructions and review the operation of all accessories provided.
To begin the test, close the Utility source circuit breaker. Referring to Figure 7, the controller will illuminate the
Utility Available LED when proper voltage is sensed. If the ATS mechanism is set on S1, the S1 position LED will also light.. Verify the phase to phase voltages at the Utility line terminals.
Next, close the Generator source breaker and start the engine generator. The S2 (Generator) Available LED will illuminate when proper voltage and frequency levels are sensed. After both sources have been verified, shut down the engine generator, and put the generator’s start control in the automatic position. Complete the visual inspection of the transfer switch, and replace the cabinet
cover (or close the cabinet door).
Simulate a utility outage by opening the S1 Utility side breaker. The delay to engine start timer (P) begins its timing cycle. After the P timer has completed its timing cycle, the engine start contacts close to start the generator.
When generator voltage and frequency reach the preset restore points (see Table 4) the S2 Available LED illumi- nates. Simultaneously, the delay to generator timer (W) begins its timing cycle. When the W time delay is com- pleted the ATS will transfer to Generator, the S1 position
LED goes off, and the S2 position LED illuminates.
Reclose the Utility breaker to retransfer to utility. The delay to utility timer (T) begins its timing cycle (Table
3). When the T timer has completed its timing cycle, the ATS will transfer. The optional S2 position LEDs go off, and the S1 position LED illuminates. The delay engine stop timer (U) begins its timing cycle. The generator runs unloaded for the duration of the U timing cycle. When the timer completes its timing cycle, the generator
will stop. The S2 Available LED goes off.
ATS Timing Cycle
Action | P Timer | W Timer | T Timer | U Timer |
| P - 5 sec. | W - 20 sec. | T - 5 min. | U - 5 min. |
S1 Fail or | Time Delay | Time Delay | Time Delay | Time Delay |
Test or | S2 Start | S2 Stable | S1 Stable | S2 Stop |
Exerciser |
|
|
|
|
| Transfer to S2 | Retransfer to S1 | Engine | |
S1 returns or Test/Exerciser Ends
Table 3
Preset Settings
Utility | Generator | ||
S1 Fail Voltage | 80% Nominal Line Voltage | S2 Fail Voltage | 80% Nominal Line Voltage |
S1 Restore | 90% Nominal Line Voltage | S2 Restore Voltage | 90% Nominal Line Voltage |
S1 Fail Frequency | 80% | S2 Fail Frequency | 90% |
S1 Restore Frequency | 90% | S2 Restore Frequency | 95% |
|
|
|
|
| Timers |
| |
P Timer | W Timer | T Timer | U Timer |
P - 5 sec. | W - 20 sec. | T - 5 min. | U - 5 min. |
Table 4
■ GE Zenith Controls | ZTX Operation and Maintenance Manual | 5 ■ |
