SPAL brushless fan

[Bitsyncmaster]

I got the SPAL brushless fan for testing.

Part numbers on the fan:
VA109-ABL321
P/N-109A/SH 12V
10 R-05 8155

Very nice build quality. Cables are long and fan power wires look to be 10 AWG. The fan requires using their temperature sender which has electronics inside the sender that drive a control signal to the fan which turns the fan on via a pulse width signal (looks like the driver is open collector) and the fan electronics capacitor couples that signal to its electronics. The fan blades have a ring around the outside that spins with the blades. I think that is a good design for fan blade efficiency.

The temperature sender has four wires, Ground, Switched 12 volts, force full power (12 volts drives fan to full power) and the sensor output wired to the fan signal input. I will be testing that sender output to make a table of PW values at each temperature. So there are no relays and only one control input that forces the fan to full power.

The fan ramps up which takes 16 seconds to reach full speed. I think the ramp up time should be 5 seconds or less which would give engine idle speed control plenty of time to adjust to the added load.

The standby current of the fan is 36 ua. @ 12.5 volts which is very good for standby current.

The fan draws 22 amps in free air at 13.0 volts on the fan power. With the fan sitting on the OEM radiator that full speed current is 27 amps. So I would guess if I had the AC condenser also resisting air flow the full speed current would be around 30 amps.

[Bitsyncmaster]

My thoughts about using this fan for the DeLorean. Definitely to much current (power) for the need to keep our engine at proper temperature and AC working well.

Even if the fans would run lower currents (not run at full speed) you still need to have the fans running about 7 to 10 amps when the AC is on. So you would need to build a PW controller to run the fan when the AC is on and engine cooling is not turning the fan on.

Even running one fan would still be overkill for the DeLorean and not sure if one fan efficiency would even equal a double fan setup.

Mounting the fans on a stock shroud would be pretty easy. I would cut the shroud so the fans could be mounted at the same distance as the OEM fan blades sit.

At 30 amps I'm sure these fans will move more air than OEM fans. I was going to test air flow but could not find my hot wire anemometer. I put it in a safe space and forgot where that was.

Now you may want to use these fans in another car that needs more air flow.

Maybe someday they will sell lower power units.

[FABombjoy]

Having the driver built-in solves a several problems for PWM fan control, at least with something like Megasquirt. The question has always been which "black box" to integrate into the setup that's most applicable to the fans being used. Many of the aftermarket fan controllers don't post specs, so you have to guesstimate current capacity based on the OEM integration then reverse-engineer the control modes & ranges. If it's engineered-in for this specific fan, problem solved! As long as the frequency is within range of the EFI controller, anyway. PWM frequency seems to be the only specification not listed in the "drive control modes" PDF but is probably available somewhere. Looking forward to reading your results!

https://www.spalautomotive.it/docume...5-b7cfc4486ddb

[Helirich]

What do they give you for instructions? Is the wire that puts them at full speed intended for AC? Would I be right to assume the ground and switched 12V carry all the current running the fan? (The other two wires are small gauge/small current)

I'm completely out of my depth in electronics, so bear with me. I'm totally guessing that the actual temp sender is a verible resistance like most standard temp senders. But on the back of it is additional electronics to convert that signal to the PWM. Is that what you figure? If so, Do you think the sender could be separated from the electronics?

Here's my logic.

I tend to agree with you that this fan won't be suitable for the Delorean. The only way I see it working is mounting two of them as stock. I understand that you can run two fans off one sender. Since the temp controls the fan speed, that setup would probably work fine for the engine cooling. Probably the fans would never run full speed because they throw so much air. So maybe they would draw less power than a stock setup. The problem is when the AC comes on the full speed wire gets triggered and the amp draw goes through the roof. If there was a way to seperate the sender from the electronics and install a resistor in line, you could make the full power wire be a 1/2 power wire. (Or whatever speed you choose) Unless you do this, you would have to install all new wires to handle the load.

If that was possible, the question is there any benifit? If you could deturmin amp draw at a given air flow is less than a stock fan, there could be. But as it stands, it appears that the amp draw will be the same or worse. I guess what I'm saying is the manufacturer is lying.

Do you have amp draw numbers for a stock fan and the newer stock fan replacements?

[Bitsyncmaster]

A resistor would not work for many reasons. One it would have to be over 100 watts. Two, it would drop the voltage to the fan and it's electronics and the spec is 13 volts to 15 volts I think.

The fan has 3 wires. Power, ground and signal input. Yes the sensor runs on a switched power and it draws 1.6 ma. when powered.

I ran the sensor in hot water. Sensor power at 14.00 volts and a 2.7 Kohm pull up resistor to 14 volts on it's output wire. I then heated the water unit the PWM maxed out at 92% duty cycle. The frequency remains at 121 Hz. I let it cool down and recorded the duty as follows.

Above 185 deg/F = max 92%
180 deg/F = 74%
175 deg/F = 57%
170 deg/F = 42%
165 deg/F = 23%
it switched off (0%) at 161 deg/F

When I get a chance I will read the fan currents with those PWM values applied. It would be simple to use a micro to make a controller but I will just use a signal generator driving a MOSFET to test the fan.

Stock fans I have seen as high as 15 amps each but normally I see around 13 amps each. Vendors lower power fans run 6 to 9 amps each but there was a vendor in UK selling 3 amp fans.

[Helirich]

A resistor would not work for many reasons. One it would have to be over 100 watts. Two, it would drop the voltage to the fan and it's electronics and the spec is 13 volts to 15 volts I think.

Stock fans I have seen as high as 15 amps each but normally I see around 13 amps each. Vendors lower power fans run 6 to 9 amps each but there was a vendor in UK selling 3 amp fans.

I didn't explain myself good. I was not suggesting a resistor between power and the fan. I was suggesting a resistor between the actual temp sensor and the electronics that convert the signal to PWM. (If that's possible) I still believe the actual sender is nothing more than a veri-resistor. I don't know why they didn't put the PWM electronics on the fan motor rather than the sender. I assume so they could run two (or more) fans off one sender. That would be cost effective to big manufacturers like GM/Ford.

Is the sender completely potted? I suppose it will be hard to dissect without destroying it.

This is all interesting, but I still think it would be real hard to justify these fans compared to the venders offerings. The 3 amp fan sounds amazing. I wonder if it only works in a cold country. Lol.

[Bitsyncmaster]

I didn't explain myself good. I was not suggesting a resistor between power and the fan. I was suggesting a resistor between the actual temp sensor and the electronics that convert the signal to PWM. (If that's possible) I still believe the actual sender is nothing more than a veri-resistor. I don't know why they didn't put the PWM electronics on the fan motor rather than the sender. I assume so they could run two (or more) fans off one sender. That would be cost effective to big manufacturers like GM/Ford.

Is the sender completely potted? I suppose it will be hard to dissect without destroying it.

This is all interesting, but I still think it would be real hard to justify these fans compared to the venders offerings. The 3 amp fan sounds amazing. I wonder if it only works in a cold country. Lol.

The sender is potted so the electronics inside the sender convert the resistance of the sensor to a digital signal pulse width modulated. I'm assuming the electronics inside the sender has a microprocessor since the frequency of the PWM seems very stable and is based off the micro clock.

The fan then has electronics inside it to decode that sensor PWM into fan speed. It also probably has a micro to do that decoding and do the ramp up time. They probably could have done all the electronics in the fan but then long cables might cause noise of the sender resistance.

I talked with one owner of the 3 amp fans (this caused problems with my electronic fused fan fail) and he said his car stayed cool. But I would not want to test that here in Maryland.

By the way this sender has 3/8" pipe tap (tapered threads).

[Bitsyncmaster]

Well I decided to make a controller to test the fan. Pretty simple since my fuel gauge circuit board is already set up to do PWM. Well what do you know, if I set the micro clock to 125 Khz the lowest PWM frequency is 121 Hz. So for sure they are using a micro inside the temp sensor.

[Bitsyncmaster]

Designing my micro was really easy and even the software took only 20 minuets. Very basic read the POT value and drive that to my PWM output. So here are the results with the fan sitting on the OEM radiator.

90 % or above is the max fan speed at 27 amps.
88 % = 26 amps
86 % = 24 amps
74 % = 17.0 amps where the sensor is at 180 deg/F
57 % = 8.5 amps where the sensor is at 175 deg/F
42 % = 4.5 amps where the sensor is at 170 deg/F
23 % = 1.5 amps where the sensor is at 165 deg/F

[Helirich]

Interesting.

It would really be nice to know how much air it flows at say 42%. When I get the fan, I can put a air speed indicator pitot tube in front, but I don't know that's a fair comparison. It would measure speed, not volume. Also I would need a controller. What would you charge for one?

If the fan would flow more than a stock fan at 42%, then it might be a benifit. An expensive benifit, but a benifit. Still, to make it work I would need a way to make the top speed be the 42%-57%. (Whether engine or AC) At least to keep stock wiring in the car.

I guess you haven't put a reflector on a blade and measured rpms? Would the 42% be 42% of the rpms? What I mean is, the fan is supposed to spin from 1000 to 4000 rpms. So would 50% be 2500?