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Controller advice

Posted: Thu Aug 09, 2007 3:45 pm
by pyoorkate
Right, Nikki suggested I ring Curtis and have a chat to them about the controller for the Enfield; I'm assuming here it needs replacement.

The Enfield as I understand it has a 10kW Series DC motor and is a 48Volt vehicle as standard.

Having spoken to Curtis they do no suitable controller; were we to have a fit of monetary spending and turn the Enfield into a 72V vehicle (which I understand is just hunky dory with the motor) we can use a Curtis 1221. Obviously then there's a lot of other sundry work.

Does anyone have any controller recommendations for the Enfield running on it's standard 48V - because I reckon that getting away with upgrading it is pushing our luck somewhat.

Posted: Thu Aug 09, 2007 4:00 pm
by electricvehicles
Why not use a Curtis 1209 48-72 Volt controller fitted with a PB6 pot box, and a an albright SW202 changeover contactor for forward/reverse select?
Controller is rated at 400A and will easily handle the motor.
Just as it happens I have a new Curtis 1209 controller going spare :lol:
And can supply all the necessary hardware that is needed

Posted: Thu Aug 09, 2007 8:01 pm
by pyoorkate
The reason I didn't go with a 1209 was because the Curtis engineers reckoned they didn't do a suitable controller; or is that an old controller they no longer make?

Posted: Thu Aug 09, 2007 9:42 pm
by EVguru
Experience from several people has shown that a 400 Amp controller is entirely inadequate for an Enfield. Going to 72 volt means you can at least use a 550 Amp 1231C (As fitted to the famous 'Sugarlump'), which just about gives reasonable acceleration. Some people don't like electronic controllers in their Enfields at all, becuse the performance is not as good as the original contactor controller. Acceleration is quite good at 1500 Amp (momentary!). Some of the original Electricity Council Enfields were fitted with 1200 Amp Cableform controllers I think.

I've got a line on Italian controllers up to 800 amp, that would work on 48 Volt or higher, but I'll have to look the link up at work.

My Apologies

Posted: Mon Aug 13, 2007 8:51 am
by electricvehicles
Sorry I thought the Enfield was running on 72V. 1209 controller will be OK at 72V but not at 48V You would be needing a controller peaking at 750A. To my knowledge I dont know of anyone who makes one, well not off the shelf. I do know of a few people who can upgrade their 600A controllers but warranty is an issue. One option might be to use the good old fashioned Cableform MK SCR Controller. Commonly used on milk floats, nice simple open frame design and upgradable by fitting additional SCRs and up rated diodes etc. But warranty and reliabily might be an issue.
Sorry I cant be of more help.

Posted: Mon Aug 13, 2007 9:38 am
by EVguru
I repeat, even at 72 volt, Enfield owners who have tried the 1209 have found the acceleration inadequate. You would probably also experience overheating of the controller.

This company in Italy sells high current low voltage controllers;

I've no direct experience with their products, but I'd go for at least the 800 Amp model to replace a contactor controller.

An SCR controller is an option, but they tend to give 10-15% less range than a Mosfet controller and the whining and growling can be a real problem in a passenger vehice. A milkfloat would usually only use the controller to smooth the acceleration and then run at full throttle with the controller effectively bypassed. A passenger vehicle is likely to spend a lot of time being driven at part throttle and the controller noise can become VERY anoying.

If the insurance company will only sanction direct replacements, then the original contactors can probably be repaired. The contacts can be replaced or re-faced and the energising coils can be replaced or even re-wound if necessary.

There's a further approach that was used in EV racing before high current controllers became available. The field coils of the motor are split into two sets and also the connections to the brushes. Two Curtis controllers can them be used on the same motor with the trottles (mechanically) in parallel.

Posted: Mon Aug 13, 2007 8:29 pm
by pyoorkate
Well, at this stage it looks like the insurance company want to write it off as an uneconomical to repair vehicle. So, plan is to agree a purchase price with them; let them write it off, and then we'll have some money to play with.

Get it fixed, engineer's report, and back on the road.

...I wonder if we can 72 volt it :)

Kate E

Posted: Mon Aug 13, 2007 8:55 pm
by qdos
Not surprised at the Insurance company's write off decision as most claims wind up being over £1500 for a minor fender bender regardless of how minor it is. That's what happens when insurance forks out for anything even a pet dog's vet bill. The prices just go up cos someone else pays.

Basically any car that's over 10 years old will be a write off if there's any form of claim on it. Insurance is a con. Make sure you get to keep the car it's not theirs unless you sell it to them. Out of interest who is it that you are insured with?

Posted: Mon Aug 13, 2007 9:07 pm
by pyoorkate
Well, it's partially our fault. My mum insured it for way too little; it should have been agreed value 3000+, my mum did it for the purchase price :-(

It's Footman James.

Really though, I expected this and am quite happy with this outcome.

Posted: Mon Aug 13, 2007 9:11 pm
by qdos
A happy outcome is a good outcome :)