ARTICLES
AC Motor Drives
Many liveaboards are facing a growing demand for power onboard.
Fitting additional dive compressor? Nitrox unit? Larger capacity water maker? There are many cases where existing generators are unable to start all the machinery onboard.
The usual solution used to be to install a larger genset. This was OK in a past era of super cheap fuel, but nowadays with rising fuel costs, oversized fuel-hungry generators are best to be avoided.
With a cost of AC inverter drives getting cheaper, they are becoming a feasible alternative to oversized generators.
Correct drive unit selection with proper installation and setup , will have quite a few advantages over a classic soft starter, Delta-Y configuration or a simple contactor motor starter.
Here are few of these advantages:
- Proper ramp/start stop will NEVER draw more than a nominal motor current.
- Slow start, but the starting torque can be 200% nominal even at 0 RPM!, which is very useful for anchor windlass, dive compressor and other loads which require hugh starting torque.
- With proper control, speed, torque and power usage can be reduced or increased from nominal motor speed. Sometimes for example we need to slow down the windlass, but keep the torque unchanged.
- Power factor improvement from average 0.8 to unity, means the real power required from the generator will be about 20-20% lower.
Check also AC Drives product page