Miller Electric Metro 250D Owner's Manual page 47

10.8 Power Required to Start Motor
1 Motor Start Code
2 Running Amperage
3 Motor HP
4 Motor 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.
10.9 How Much Power Can Generator Supply?
1 Limit 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.
OM-402
4
1
3
Single-Phase Induction Motor Starting Requirements
Motor Start
Code G H
KVA/HP 6.3 7.1
kVA/HP x HP x 1000
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
230
AC MOTOR
VOLTS 230 AMPS 2.5
CODE M Hz 60
HP 1/4 PHASE 1
J K L M
8.0 9.0 10.0 11.2
= STARTING AMPERAGE
Starting the motor requires 12.2 amperes.
1
2
S-0624
2
N P
12.5 14.0
Ref. ST-800 396-A / S-0625
43