Generator Tests Under Load, Do not Overload

Section 3 — Operation

Generac GTS “HS” Type Transfer Switch

DANGER

PROCEED WITH CAUTION. GENERATOR OUT- PUT VOLTAGE IS NOW BEING DELIVERED TO TRANSFER SWITCH TERMINALS. CONTACT WITH LIVE TERMINALS RESULTS IN EXTREMELY DANGEROUS AND POSSIBLY FATAL ELECTRI- CAL SHOCK.

7.With an accurate AC voltmeter and frequency meter, check the no-load, voltage and frequency. Single-phase generator supply:

Measure across ATS terminal lugs E1 to E2. Also check E1 to NEUTRAL and E2 to NEUTRAL.

a. Frequency	60-62 Hertz
b. Terminals E1 to E2	240-246 VAC
c. Terminals E1 to NEUTRAL	120-123 VAC
d. Terminals E2 to NEUTRAL	120-123 VAC

8.Set the generator’s main circuit breaker (CB1) to its OFF or OPEN position.

9.Set the AUTO/OFF/MANUAL switch to the OFF position to shut down the generator.

NOTE:

Do NOT proceed until generator AC output voltage and frequency are correct and within stated limits. If the no-load voltage is correct but no-load fre- quency is incorrect, the engine governed speed probably requires adjustment. If no-load frequen- cy is correct but voltage is not, the voltage regula- tor may require adjustment.

3.4GENERATOR TESTS UNDER LOAD

1.Set the generator's main circuit breaker to its OFF or OPEN position.

2.Manually actuate the transfer switch main con- tacts to their EMERGENCY (STANDBY) position. Refer to Manual Operation (Section 3.2).

3.To start the generator, set the AUTO-OFF- MANUAL switch to MANUAL. When engine starts, let it stabilize for a few minutes.

4.Turn the generator's main circuit breaker to its ON or CLOSED position. The generator now pow- ers all LOAD circuits. Check generator operation under load as follows:

•Turn ON electrical loads to the full rated wattage/amperage capacity of the generator.

DO NOT OVERLOAD.

•With maximum rated load applied, check voltage and frequency across transfer switch terminals E1 and E2. Voltage should be greater than 230 volts and frequency should be greater than 59 Hertz.

•Let the generator run under rated load for at least 30 minutes. With unit running, listen for unusual noises, vibration, overheating, etc., that might indicate a problem.

5.When checkout under load is complete, set main circuit breaker of the generator to its OFF or OPEN position.

6.Let the generator run at no-load for several minutes. Then, shut down by setting the AUTO- OFF-MANUAL switch to its OFF position.

7.Move the switch's main contacts back to their UTILITY position. For example, load connected to UTILITY power supply. Refer to Manual Operation (Section 3.2). Handle and operating lever of transfer switch should be in UP position.

8.Turn on the utility power supply to transfer switch, using whatever means provided (such as a utility main line circuit breaker). The utility power source now powers the loads.

9.Set the generator's AUTO-OFF-MANUAL switch to its AUTO position. The system is now set for fully automatic operation.

6 Generac® Power Systems, Inc.