Miller Electric Metro 250D Power Required to Start Motor, How Much Power Can Generator Supply?

10.8 Power Required to Start Motor

1Motor Start Code

2Running Amperage

3Motor HP

4Motor Voltage

To find starting amperage:

Step 1: Find code and use table to find kVA/HP. If code is not listed, multiply running amperage by six to find starting amperage.

Step 2: Find Motor HP and Volts.

Step 3: Determine starting amper- age (see example).

Welding generator amperage out- put must be at least twice the motor’s running amperage.

S-0624

4
		AC MOTOR			2
1
	VOLTS	230	AMPS	2.5
3	CODE	M	Hz	60
	HP	1/4	PHASE 1

Single-Phase Induction Motor Starting Requirements

Motor Start	G	H	J	K	L	M	N	P
Code
KVA/HP	6.3	7.1	8.0	9.0	10.0	11.2	12.5	14.0

kVA/HP x HP x 1000 = STARTING AMPERAGE VOLTS

EXAMPLE: Calculate the starting amperage required for a 230 V, 1/4

HP motor with a motor start code of M.

Volts = 230 HP = 1/4 Using Table, Code M results in kVA/HP = 11.2

11.2 x 1/4 x 1000	= 12.2 A	Starting the motor requires 12.2 amperes.
230

10.9 How Much Power Can Generator Supply?

1Limit Load To 90% Of Generator Output

Always start non-resistive (motor) loads in order from largest to small- est, and add resistive loads last.

2 5 Second Rule

If motor does not start within 5 seconds, turn off power to prevent motor damage. Motor requires more power than generator can supply.

Ref. ST-800 396-A / S-0625

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OM-402 43