Behlman Solutions

Motor Testing

PROBLEM:

Starting a motor which has a running current near the maximum current of a BEHLMAN AC Power Supply.

SOLUTION:

Starting a motor can require between 6 and 10 times the running current of the motor. This current is required for a long time, which can be seconds and is not the same as the peak current available for running power supplies, which is only there for a fraction of a cycle. Don't get the two confused. In the past it was necessary to size the AC power supply to the starting current and not the running Current.

The MT does not supply the 140 Amps of starting current, but folds back the voltage and brings the motor up slowly with what we call a "Soft Start". This is good for production testing because the motor starts without the "jerk" which normally requires it to be restrained. Production testing is able to be accomplished in less time with one less step (holding the motor down). We have rated the BL1350-MT at 14 Amps (50% duty cycle) and able to start motors which would normally require up to 140 Amps of starting current.

Since the introduction of the BL and BL-HP, manufacturers have wanted to use it in factory for production testing. In one particular case, a manufacturer of vacuum cleaner motors wanted to perform production testing on motors which have running currents as high as 14 Amps and starting current as high as 140 Amps. To solve this problem we supplied a Motor Tester (MT) version of the BL1350. It worked so well that we expanded the MT to the BL-HP Series. The MT is available on both BL1350 and BL-HP Units. 

The MT also lends itself to testing devices such as transformers which might have a large initial surge (an actual case).

See Specification sheets BL & BL-HP for additional information on MT option.