- Thread starter langy
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brightspark
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to run a 7hp 415v u would need a 10hp either static or a rotary converter to cope with the starting load .statics are about £650 rotary are about £1000
unless u can pick something up second hand. il post later im getting some info on the 415v digital
unless u can pick something up second hand. il post later im getting some info on the 415v digital
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Hello Langy,
try this company for advice, I've found them helpful in the past, and they do 240 v single to 415 v three phase units.
http://www.drivesdirect.co.uk/index.htm
Alec
try this company for advice, I've found them helpful in the past, and they do 240 v single to 415 v three phase units.
http://www.drivesdirect.co.uk/index.htm
Alec
Shox Dr
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5.5kw is 7.5hp. Not cheap, as BS says. I was really lucky the other day and picked a 7.5hp rotary inverter off fleabay for 100quid, the guy said it was cutting out. Only needed one capacitor, replaced all 3 for £25 and it runs like new.
I'd take the compressor and keep a lookout for a cheap inverter on fleabay
Just bear in mind if you go for a Rotary, it will need to be running all the time for the compressor to kick-in when needed. So a VFR would be a better choice, but they are even more
I'd take the compressor and keep a lookout for a cheap inverter on fleabay
Just bear in mind if you go for a Rotary, it will need to be running all the time for the compressor to kick-in when needed. So a VFR would be a better choice, but they are even more
brightspark
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a 7.5hp digital 415 converter will cost u £750 thats a light duty one .for the 7.5 hp[ on the compressor u would need to buy the 10 hp heavy duty one to cope with the starting load and the cost is £"1000
langy
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Thanks for that but i already deal with them, I have a 3hp & 4hp unit, they are excellent people to deal with.
langy
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If you decide not to have it I would be interested, a mates compressor has just gone pop and he needs a good one soon as.
langy
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Its in Uxbridge, Middlesex Tigler, buzz me on 07836 244483 and you can have it for what it was offered to me for, Its cheap 
langy
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graffian
Seer unto the end of his beard
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Tell me more now you have my interest
Rotary converters are pretty simple, look up rotary converters and you will find lot's of yank sites[ fitch williams's ramblings/designs seem pretty sound]. Basically I made the same as his converters. Using 415V means you only need a fraction of the capacitance they talk about . I have a 240 to 415V transformer at the input to the converter, that's the only way mine differs really. oh and spetics use a potential switch to switch the caps, which can easily be done with a few electronics components[they are the bit's on the
terminal block on the left hand side wall of the box].
I wired the garage and shed from the converter so I turn the converter on and the machines work on their original switches and stuff.
Image below is the inside of the box on the wall, the motor, transformer and one lot of run capacitors are in a box on the floor. The caps in the image are the start caps and run caps which are switched automatically when you switch it on. It's been in use since 2003, I will get round to finishing it one day;-)
If you want to have a go I can give you a pdf wiring diagram, I didn't actually do a diagram while I was building mine, I drew it for someone some time after I made mine. I just laid the bit's out on a bench and experimented a bit till I had a balanced voltage under load. It should be fine running 10hp all day long's but was tuned with a 3hp lathe taking a heavy cut.
langy
langys rodshop
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langy
langys rodshop
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Thanks for taking the time to type that up
Its very interesting.
Its very interesting.
Rotary converters are pretty simple, look up rotary converters and you will find lot's of yank sites[ fitch williams's ramblings/designs seem pretty sound]. Basically I made the same as his converters. Using 415V means you only need a fraction of the capacitance they talk about . I have a 240 to 415V transformer at the input to the converter, that's the only way mine differs really. oh and spetics use a potential switch to switch the caps, which can easily be done with a few electronics components[they are the bit's on the
terminal block on the left hand side wall of the box].
I wired the garage and shed from the converter so I turn the converter on and the machines work on their original switches and stuff.
Image below is the inside of the box on the wall, the motor, transformer and one lot of run capacitors are in a box on the floor. The caps in the image are the start caps and run caps which are switched automatically when you switch it on. It's been in use since 2003, I will get round to finishing it one day;-)
If you want to have a go I can give you a pdf wiring diagram, I didn't actually do a diagram while I was building mine, I drew it for someone some time after I made mine. I just laid the bit's out on a bench and experimented a bit till I had a balanced voltage under load. It should be fine running 10hp all day long's but was tuned with a 3hp lathe taking a heavy cut.
Yes, just trying to arrange a trip down to pick it up. The way it's looking it will probably be Wednesday. Would like to have a sneaky visit to the Ace too but I doubt I'll have time
