Winegrowers Supplies
- power inverters - some advice
If you wish to use machinery which has a 3-phase (380/400 volt) motor, but you do not have a 3-phase electricity supply there are two options:-
1. Buy a 3-phase inverter.
There are many types and sizes, for example, for smaller machines:-
http://www.machinemart.co.uk/shop/product/details/pc-40-3-5hp-phase-converter/path/transformers-inverters-phase-converters-sol
The Clarke PC-40 is a compact power converter - designed
to enable 400 volt, 3-phase motors & equipment to operate when only 230 volt
mains power is available; it converts 230 volt 1-phase input into 380-415 volt 3-phase
output. The PC-40 has adjustable power output to match the requirements of motors up to a max. of 3.5 hp (2.61 kWatt).
The PC-40 just works successfully to power a Voran 100P2 pack press with AMH mill
running, although it must be wired through a 20 amp MCB to allow for short peak
loads; it should not be connected to a 13 amp socket.
There is also a PC-60 model which is for up to 5.5 hp (4.1 kWatt). This must be wired through a 32 amp MCB.
Note: It is essential to choose an inverter with at least 2x the power of the motor, and preferably 3x for some types of motor (eg. mohno-pumps), in order to allow for starting current. 1.0 horsepower (electric) = 0.746 kWatt.
For larger motors I suggest talking to an expert, David on 01623 720 730.
http://stores.ebay.co.uk/Drives-Direct-Inverters-LTD?_trksid=p4340.l2563
- First read 'How to Choose'.
He sells various models, 3.0 hp (£450 incl Vat), 5.0 hp (£775 incl Vat), and 7.5 hp (£895 incl Vat) which needs to be wired up to a 40 amp single phase supply (through a separate MCB, like an oven is). These have soft start, and the ability of speed control by frequency inversion provided your electrician connects it up (via an external starter) directly to the motor, bypassing the on/off switch on the motor of your machine.
Or if your motor is dual-voltage then you could have it re-wired as 230 volt 3-phase, and use an inverter from 230 volt 1-phase input to 230 volt 3-phase output, which is much smaller and cheaper than a 380 volt inverter.
or
2. Replace the 3-phase motor with a single-phase one, of suitable power.
Note: all electrical work needs to be carried out by a qualified electrician.