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dg2010
05-14-2010, 03:12 PM
Having initially intended building Zero's PWM but I was offered locally a Maxx Tronic MX067.

I have now wired this up but is not making much sense to me. I have discovered that it will not work if the cell is grounded to the chassis which creates a big problem in mounting it.

For information the cell is -5N+5N- configuration with an internal 130mm square effective area. Without the PWM it runs at 21 amps or 14 at tickover, does not heat nor does the amperage increase. With the PWM installed and the cell not grounded it will not run over 14 amps. Grounding it will then take it up to 21 again. I am using a 25% solution by weight though using a weaker solution does not make much difference.

Maybe the cheap Chinese meter is lying but it is protected by 20 amp fuse.

I am a bit puzzled over this. I am tempted to ditch the PWM.

Would welcome any comments.

cabrera
05-14-2010, 05:47 PM
Having initially intended building Zero's PWM but I was offered locally a Maxx Tronic MX067.

I have now wired this up but is not making much sense to me. I have discovered that it will not work if the cell is grounded to the chassis which creates a big problem in mounting it.

For information the cell is -5N+5N- configuration with an internal 130mm square effective area. Without the PWM it runs at 21 amps or 14 at tickover, does not heat nor does the amperage increase. With the PWM installed and the cell not grounded it will not run over 14 amps. Grounding it will then take it up to 21 again. I am using a 25% solution by weight though using a weaker solution does not make much difference.

Maybe the cheap Chinese meter is lying but it is protected by 20 amp fuse.

I am a bit puzzled over this. I am tempted to ditch the PWM.

Would welcome any comments.
You can't ground your cell to the chassis. It must take it's ground directly from the PWM since it is the ground connection that is "pulsed" by the PWM.

I originally installed something like the Maxx Tronic MX067. I have now bought a CCPWM ZFF. It's a much better unit and is rated at 150a (even though it will never see that amperage).
The big problem I foresee with the Maxx Tronic MX067 is the use of spades to connect the positive & negative wires. Heat will eventually weaken the solders on the circuit board and you will have issues.
Your only solution, with any PWM is to run pos & Neg wiring to & from the PWM & Upgrade to the zero unit when you can.

dg2010
05-14-2010, 06:02 PM
You can't ground your cell to the chassis. It must take it's ground directly from the PWM since it is the ground connection that is "pulsed" by the PWM.

I originally installed something like the Maxx Tronic MX067. I have now bought a CCPWM ZFF. It's a much better unit and is rated at 150a (even though it will never see that amperage).
The big problem I foresee with the Maxx Tronic MX067 is the use of spades to connect the positive & negative wires. Heat will eventually weaken the solders on the circuit board and you will have issues.
Your only solution, with any PWM is to run pos & Neg wiring to & from the PWM & Upgrade to the zero unit when you can.

Thanks for the reply.

Think I will revert to running it straight for the time being and monitor how it behaves. Never anticipated having to run it off ground.

I am puzzled why when it is insulated that I cannot reach the amperage when run without the PWM.

rcflyn
05-27-2010, 11:39 PM
Thanks for the reply.

Think I will revert to running it straight for the time being and monitor how it behaves. Never anticipated having to run it off ground.

I am puzzled why when it is insulated that I cannot reach the amperage when run without the PWM.


Ok, This isn't making much sence here.... Insulating, or Isolating the unit shouldn't have any effect on attaining desired amperage, be it WITH, or WITHOUT a PWM.... Sounds to me like you don't have your E-Lyte concentration set high enough to draw your desired amperage...
The PWM Turns on and shuts off the power very rapidly, hence, the need for the ground to go to the unit. but, by no means, will the PWM the make the unit accept MORE amperage than it'll take... Meaning, if you have EVERYTHING dialed in (MINUS the PWM) so the Unit Pulls 10 amps, Then the PWM WILL NOT Make the unit run at 20 amps....
The PWM Will however, Drop, and Maintain a unit pulling 30 amps,to ONLY run on 20 amps....

rcflyn
05-27-2010, 11:43 PM
You can't ground your cell to the chassis. It must take it's ground directly from the PWM since it is the ground connection that is "pulsed" by the PWM.

I originally installed something like the Maxx Tronic MX067. I have now bought a CCPWM ZFF. It's a much better unit and is rated at 150a (even though it will never see that amperage).
The big problem I foresee with the Maxx Tronic MX067 is the use of spades to connect the positive & negative wires. Heat will eventually weaken the solders on the circuit board and you will have issues.
Your only solution, with any PWM is to run pos & Neg wiring to & from the PWM & Upgrade to the zero unit when you can.

So how are you liking that unit so far Andy??? Is it Installed on the TRAC already???
With All the Irons I've got in my Fire, I STILL haven't even thought of hooking eiter one of mine up to see how well they'll work. Once the Beemer's Reactor is installed, I'm sure I'll start fiddling with them though...

dg2010
05-28-2010, 05:07 AM
Ok, This isn't making much sence here.... Insulating, or Isolating the unit shouldn't have any effect on attaining desired amperage, be it WITH, or WITHOUT a PWM.... Sounds to me like you don't have your E-Lyte concentration set high enough to draw your desired amperage...
The PWM Turns on and shuts off the power very rapidly, hence, the need for the ground to go to the unit. but, by no means, will the PWM the make the unit accept MORE amperage than it'll take... Meaning, if you have EVERYTHING dialed in (MINUS the PWM) so the Unit Pulls 10 amps, Then the PWM WILL NOT Make the unit run at 20 amps....
The PWM Will however, Drop, and Maintain a unit pulling 30 amps,to ONLY run on 20 amps....

Thanks

I think I need to check my wiring on this as I have a feeling I have put in a resistance with using the wrong gauge.

borescopeit
02-25-2011, 07:01 PM
Most PWMsdo use N-channel POWER MOSFETS that have negative source/drain terminals. Thus you cannot run positive wire through your PWM. Your negative terminal side of the cell should be insulated from the chassis. Install high amp relay on positive wire + appropriate fuse there.