Quickie P320 brake Problem (moved from Football thread)

[retiredarmy]

I am currently a retired service engineer from an international manufacturer of packaging machinery and need some help.

I am currently volunteering as "Equipment Manager" for a Power Chair Soccer Team here in the Tampa Bay Area and have been disassembling chairs and painting them in a scheme of team colors. When I put a Quickie P320 back together it appears that the left drive is either not driving or the brake is not releasing.

I have checked the 2 microswitches that are involved in the seat removal and assume that they prohibit chair movement if the seat should come loose. I am only guessing and have searched the internet for wiring diagrams/schematics to no avail. Are there any wiring diagrams out there anywhere?

Regionals in Atlanta are coming up and I would like to be well versed in how these chairs work and need some help, please. These sports people look forward each week for practice and I don't want to disappoint them by having any down time.

Your assistance is appreciated.

RA

[JoeC]

Hi RA, I haven't had my hands on a P320, but I can tell you a little bit about how the P200 is wired. The P200 has one microswitch that is normally open, and gets clicked closed when the seat is firmly attached. There is a second switch inside the motor housing by the brake that is normally open, and gets clicked closed when the brake lever is engaged to allow the parking brake to engage and disengage electrically.

Both switches are wired in series, with the parking brake in series with the switches. The motor controller senses a short circuit regardless of whether it is engaging the brakes or not. The brake current is only an amp or two, so if you need to replace the switches you shouldn't have a problem finding a good replacement, as long as the fit is right.

To check if what I've said is right and applies to your model, you can try shorting both switches with pieces of wire, obviously not shorting the brake! With the chair up on blocks, you should be able to get everything to drive and move normally.

The most common problem I see is the switch for the seat clamp getting knocked down out of position, and not getting reliably clicked when the seat is in place.

Generally I would say that the chair would sit still and flash an error code at you if there was anything wrong with the brakes. Is it possible that the brake is shorted out somehow, or has a mechanical interference stopping it from being released?

[retiredarmy]

Thanks Joe and I'll check on that as soon as I can and get back to you.

Thanks for the fast response and I'm sure the kids will appreciate your help as much as I do,

RA

[retiredarmy]

By the way Elio and Jessie said to say hello to you and yours!

[JoeC]

It's good to hear from those two! I think we might be in your neck of the woods for a Team USA training camp before the cup, so maybe I'll get to say to everyone out there.

I looked up the P320 online (not easy!), and from pictures it looks like it's basically a P200 with a manual recline seat. I'll be interested to hear how it works out for you.

[retiredarmy]

Joe your help was essential in getting this fixed. I found one microswitch was bad and the other intermittent. Possibly with age they were brittle and since the seat had not been removed from the base for a long period of time maybe some dirt, drink or other fluids had got into them and when I removed the seat it completed the destruction.

I removed them both and the switches are wired to the "normally closed" position so when the seat is screwed down the (both) switches open. Maybe they were at a critical point but the chair works fine now (with the wires isolated in an open condition). I am going to wire a safety cable and crimp it so that any attempt to unscrew the hold down would require cutting the cable (non-electric). This should suffice as a safety measure temporarily until I get the replacement microswitches (from Newark Elctronics for about $3.50 each).

I wrote down the wiring from the the cable hock to the motors and switches and will create a drawing with explanations on how to trace the wiring without complete dissassembly. I'll post them (if I can) up here when I am finished with them.

Again thank for you for the help and I'll forward your comments on to Elio and Jessie. They'll be here for dinner tomorrow night!

[JoeC]

In case anybody comes across this thread in the future, I've just come across an older version of the P200 (not the newer one with P&G Pilot+ controls labeled Qtronix), and it has a different layout than the one I described before. I am still making sure that I understand it correctly.