Generac Power Systems 004945-1, 005036-0 owner manual Voltage Checks, Generator Tests Under Load

Section 3 — Operation

ATS “HS” Type Transfer Switch

3.3 VOLTAGE CHECKS NOTE:

1.Turn ON the UTILITY power supply to the trans- fer switch using the service disconnect circuit breaker.

DANGER

PROCEED WITH CAUTION. THE TRANSFER SWITCH IS NOW ELECTRICALLY HOT. CONTACT WITH LIVE TERMINALS RESULTS IN EXTREMELY HAZARDOUS AND POSSIBLY FATAL ELECTRICAL SHOCK.

2.With an accurate AC voltmeter, check for correct voltage. Measure across ATS terminal lugs N1 and N2. Also check N1 to NEUTRAL and N2 to

NEUTRAL.

3.When certain that UTILITY supply voltage is cor- rect and compatible with transfer switch ratings, turn OFF the UTILITY supply to the transfer switch.

4.On the generator panel, set the AUTO/OFF/ MANUAL switch to MANUAL position. The gen- erator should crank and start.

5.Let the generator stabilize and warm up at no- load for at least five minutes.

6.Turn the GENERATOR DISCONNECT SWITCH to the ON position.

7.Set the generator's main circuit breaker (CB1) to its ON or CLOSED position.

DANGER

PROCEED WITH CAUTION. GENERATOR OUTPUT VOLTAGE IS NOW BEING DELIVERED TO TRANSFER SWITCH TERMINALS. CONTACT WITH LIVE TERMINALS RESULTS IN EXTREMELY DANGEROUS AND POSSIBLY FATAL ELECTRICAL SHOCK.

8.With an accurate AC voltmeter and frequency meter, check the no-load, voltage and frequency. 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

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

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

Do NOT proceed until generator AC output volt- age and frequency are correct and within stated limits. If the no-load voltage is correct but no-load frequency is incorrect, the engine governed speed may require adjustment. If no-load frequency is correct but voltage is not, the voltage regulator 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 sta- bilize 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 watt- age/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 230VAC 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 connect- ed to UTILITY power supply. Refer to Manual Operation (Section 3.2). Handle and operating lever of transfer switch should be in UP posi- tion.

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.

10.Set the GENERATOR DISCONNECT SWITCH to the ON position. The system is now set for fully automatic operation.

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