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Mark viii fan / spal pwm v3 controller issues

Sorry for the late update fellas but I took a road trip down to Savannah to test out the fan setup etc. It works awesomellllly:D

Now as to how I resolved the issue; after doing alot of different forum trolling I had a light bulb moment:haha:Since the fan was only coming on when I requested AC and in conjunction with what I read on another board, it was basically an override switch function. Always on with AC on and always off with AC off. It meant that voltage was getting to the fan through the spal system by overriding the normal ignition(key-on voltage).
I double checked where I had spliced into a key-on power source and it tested good (I had used the windshiled washer pump). With a proper key-on source the spal unit should power on with key turned on and the fan should start up. This was not the case using the washer pump for power. I didnt want to tap into the fuse box, so I decided to use another source (the radio) and spliced into it. Next thing you know viola:D IT WORKED.

I programmed the spal unit and it worked well. I will make a couple mods to the system after the test run. I used another temp switch which I mounted in the waterpump neck but didnt realize that when I programmed the spal unit off of the reading from the temp switch in the block, the reading would be quite different from what the one in the waterpump neck was reading. I will now splice back into the block temp switch and reprogram the unit.
 
Be careful. From what I read, if the fan draws more than the rated amount, the unit will turn it off without any warning to you.

There is a place you can hook up a remote readout light to warn you if it goes out on overload, and the people who made it recommend you do it.
It looks like the fan you have will work fine unless it calls for full speed. Then it might hit the current limiter.

All that could be resolved by using a solid state relay, but one heavy enough to run the fan would cost more than you have in the whole system.

As for a K5, heck I could lose two in my workshop. Got to clean that place out one of these days.........
 
About the overload issue, I figured it would probably happen if I had setup the fan up in its high speed mode. There are two types of Mark8 fans and even though I have the two speed fan, I didnt hook it up using the high speed power positive terminal.

Fordum said:
Be careful. From what I read, if the fan draws more than the rated amount, the unit will turn it off without any warning to you.

There is a place you can hook up a remote readout light to warn you if it goes out on overload, and the people who made it recommend you do it.
It looks like the fan you have will work fine unless it calls for full speed. Then it might hit the current limiter.

All that could be resolved by using a solid state relay, but one heavy enough to run the fan would cost more than you have in the whole system.

As for a K5, heck I could lose two in my workshop. Got to clean that place out one of these days.........
Click to expand...
 
Update!!!!

It's been a few years since I have been on the board. I gave my K5 to a buddy (its his daily driver) two years back and the Yukon was at my parents place in Savannah. The Spal PWM Controller burnt up some time back and I drove down to Savannah and put back on the clutch fan. BUT NOW, I plan on using the truck again and I bought another Mark VIII fan.

So time to troll and figure out how to controll this bad boy:D
 
So decided to finally pull the SPAL PWM V3 Controller and see what happened inside and it anit pretty:doah:. I need to resolve this as the truck is back to full time work status. With it being cold in Ohio (my present work location), it's taking too long to warm up in morning and will be crap for A/C come summer time.

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Do yourself a favor and just wire it up using a relay and a normal on/off temp sender of the proper temp. If you want you can even wire it up with a manual override so you can turn the fan(s) on at will.
 
buddy of mine has this on his fan http://www.summitracing.com/parts/hda-3647/overview/

works great . only problem we found was heavy mud time got motor warm and we stoped and let it cool off and forgot to leave the key on for key hot . we are going to add a toggle switch for the controller to be key on/off or hot when playing so it can cool off better.
 
4X4HIGH said:
Do yourself a favor and just wire it up using a relay and a normal on/off temp sender of the proper temp. If you want you can even wire it up with a manual override so you can turn the fan(s) on at will.
Click to expand...

How do I create a system that utilizes both fan speeds? I guess it would involve two temp switches, one for each speed, and how would it shut off low speed when high speed is triggered?
 
sweetk30 said:
buddy of mine has this on his fan http://www.summitracing.com/parts/hda-3647/overview/

works great . only problem we found was heavy mud time got motor warm and we stoped and let it cool off and forgot to leave the key on for key hot . we are going to add a toggle switch for the controller to be key on/off or hot when playing so it can cool off better.
Click to expand...

Nice price but I have a dual speed fan (not dual fans). I gotta figure this out:doah:
 
Any chance you can read the numbers off the failed MOSFET? If it were my setup, I would try to mod this controller for more power before buying another whole setup.

OR-just get a 2-speed fixed control going with relays.

The controller looks complex enough to have a boost converter and use N-FETs. I don't know how much charge it can pump, but it can probably switch multiple FETs, it would just be a little slower (you can call that an advantage, lower EMI!). So you would get 2 or 3 FETs and strap them to a decent heatsink, then wire them in parallel (G, S, D). This should be no problem getting 40, 50A of capability.

But the first step would be to replace the blown FET and confirm that the controller still works. I don't know exactly which part you need, so just get one from the MOSFET drawer in your workshop. Not everybody has that? OK, it will be something like this: http://www.mouser.com/ProductDetail/International-Rectifier/IRLIZ34NPBF/?qs=sGAEpiMZZMshyDBzk1%2fWi5%252bqVgN3%252bWS8jMjODEKRMNo%3d
 
Fordum said:
The controller turns the power on full for a very short time, then turns completely off.
Since there in no point where there is any resistance, no power is wasted.

The fan starts to turn, then coasts when the power is off. To make the fan run faster, it stays on longer.
It supplies power in pulses, and varies the width, or length of time, the pulses stay on to control the speed.
Click to expand...

This isn't exactly right. It's much more efficient than a fixed resistor, but there is power lost, i.e. heat generated. There is resistance when the device is on, but it is in the milliohm range (Rds on). There is also heat from switching. Every time the FET transistions from off-on and on-off, it passes through it's linear zone where it is a resistor. This is why switching time is important. The fewer microseconds used in switching, the less heat is generated, but also more electrical noise (it's like bandwidth, the faster the pulse edge, the higher frequency content in it). These sources of heat are why this MOSFET has blown up.

Also, the fan does not coast during PWM. The motor is inductive, so the current can not change in the windings instantly. When the FET is on, the coil current is increasing. When the FET is off, the current is decreasing. The duty ratio (on time vs. total time) is varied to set the average current. The current is like a sawtooth, rising and falling around the average current. The voltage is like a square wave. When the switch is off, where does the current go? Either through a 2nd MOSFET that switches in complement to the main one, or it goes back through a flyback diode or the body diode of the MOSFET itself.
 
I'm going to have an electrician check it out but I doubt it's any good.

Blue85 said:
Any chance you can read the numbers off the failed MOSFET? If it were my setup, I would try to mod this controller for more power before buying another whole setup.

OR-just get a 2-speed fixed control going with relays.

The controller looks complex enough to have a boost converter and use N-FETs. I don't know how much charge it can pump, but it can probably switch multiple FETs, it would just be a little slower (you can call that an advantage, lower EMI!). So you would get 2 or 3 FETs and strap them to a decent heatsink, then wire them in parallel (G, S, D). This should be no problem getting 40, 50A of capability.

But the first step would be to replace the blown FET and confirm that the controller still works. I don't know exactly which part you need, so just get one from the MOSFET drawer in your workshop. Not everybody has that? OK, it will be something like this: http://www.mouser.com/ProductDetail/International-Rectifier/IRLIZ34NPBF/?qs=sGAEpiMZZMshyDBzk1%2fWi5%252bqVgN3%252bWS8jMjODEKRMNo%3d
Click to expand...
 
Just an idea, but is there another ECM out there that will work in your truck with minimal mods, that can control an electric fan?

Seems like an incredibly complex solution to a minor problem. PWM is cool and all, but even in the 80's GM was controlling on/off temps and run time for multiple electric fans, if this is a 2 speed fan, I imagine a GM ECM that could run two fans would work with the Mark VIII fans, no? You've already got a CTS input...
 
This isn't exactly right. It's much more efficient than a fixed resistor, but there is power lost, i.e. heat generated. There is resistance when the device is on, but it is in the milliohm range (Rds on).
Click to expand...

True, but remember, I was explaining PWM to people without a MOSFET drawer like we have........

Still unpacking from wrestling bears in the swamp, hope to jump back in this later tonight or tomorrow.
 
You know, life would be so much easier if we had a way to convert the fan motor to three phase AC.......
Motor controllers for them are cheap, and will handle most any load you throw at them.
But, the extension cord costs would mount up.......

Anyway, in between unpacking, and getting things set back up here at the house, I did some checking around.
Resisting an almost overpowering urge to drop back from PWM to linear and throwing some 2N3055s at it, and not wanting to reinvent the wheel, I found these:

http://www.canakit.com/50a-dc-pwm-motor-speed-controller.html

I like this one for the price, but the paperwork is sketchy, and I don't know about control options.

Then there is this one:

http://www.myskunkworks.net/servlet/the-89/Powerful-160A--dsh--12V,/Detail

Certainly should be able to handle the load, but there is no manual to be downloaded, so control options are unknown.

You would think it was basically just two of these on one board, but it does not say.

http://www.myskunkworks.net/servlet/the-79/Powerful-12V,-24V,-36V,/Detail

This is the best one I have seen. No paperwork, but the control options that are listed make it real promising.
I can see it being coupled to a basic stamp, a Raspberry Pi, or an Arduino to read a thermocouple or regular temp sending unit to control the fan speed.
 
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