Wiring Soild State Relays

[Ducie54]

Im looking at using a solid state relay to control fuel pumps and engine fans but not 100% sure on the best way to wire them. Googling shows there are several ways it can be done but you cant believe everything on the net.

Im using the Jaycar 100amp DC 4086 SSR http://www.jaycar.com.au/Electromechanical-Components/Relays-%26-Accessories/Solid-State/Solid-State-Relay-4-32VDC-Input,-30VDC-100A-Switching/p/SY4086

The SSR manual talks about using a diode to protect the relay against voltage spikes when turning off a inductive load, Another bit im unsure on.

Also is it possible to read the output voltage from the SSR to the fuel pump and have that inputted into the ECU?   

[Scott]

As far as I'm aware a solid state relay will be wired just like a normal relay. Even normal relays often come with a diode installed, as in these images:

 

http://s260.photobucket.com/user/minipitt1/media/flyback3_zps0fbba033.png.html

 

Yes, it would be possible to have the solid state relay output feed back into the ECU. You could either use a digital input channel or an analog volt channel. The digital input would give you an on/off status or a frequency (if using PWM control), and the analog volt channel would give you an actual voltage. 

[Ducie54]

So like the below pic then?

If I wanted to read the voltage to the fuel pump would I need to use the GP input function of the AN volt channel?

 

 

Edited October 19, 2015 by Ducie54

[Dave Kriedeman]

Hi Ducie54,

I use these same solid state relays to drive AUX injectors also.

The pins 3 and 4 need to be changed .

3 -  should also be a 12 volt ignition switched supply.

4 -  should be an auxiliary output set to PWM

As for the fuel pump power input back to the ECU , No you can not as the inputs are only designed to run 0 - 5 volt only.

Regards

Dave.

[Ducie54]

Thanks Dave.

Can we add a 0-12volt input to the wish list please. 

[augusto]

Hi

Assemble a resistive divider in the power cord from the electric pump.
So that the voltage at the analog input is a maximum of 5V.
And only put two resistors in series to the ground and remove the middle control voltage of the two.
I'm sorry for my english.

Augusto.

[Dave Kriedeman]

Hi Ducie54,

I spoke to Ashley and he said the following,

Divide it down by 10, so you could monitor it so at 13.7 volts it would be measured as 1.37 volts.

Will request higher voltage 0 - 14 volt or so.

Regards

Dave.

[Ducie54]

Thanks Guys

Dave im having a Dual voltage divider made, I can send it to you for testing if you would like.

Updated pic below

 

[Dave Kriedeman]

Hi Ducie 54,

I fly to Brisbane this week on Wednesday for major surgery so it might have to wait a few weeks if you want it tested on the simulator mate.

Shouldn't that divider circuit be on the Fuel Pump positive side.

Regards

Dave.

[Ducie54]

For those that are interested Ocean Controls in Australia sell dual channel voltage divides. Tested and adjusted mine on a constant battery voltage today and worked well. Still have to test which side of the SSR the signal needs to come from.

https://oceancontrols.com.au/search.php?mode=search&page=1&keep_https=yes

 

[Marty]

Did this end up working out for you Ducie 

[Ducie54]

The solid state relays work fine when wired up using the last wiring pic. I didn't end up using the voltage divider as I run out of voltage inputs. Worked fine when I connected it to the battery. When I'm on days off again I'll test it using PWM and post a log file. 

[Benny]

Quick bump,  I have followed the last diagram in this topic as well as checked other wiring diagrams and confirmed manufacturers diagram with no luck. 

Ive killed two SSR so far, at first thought the first one was faulty so exchanged but the second is the same. 

Runs for 5mins, then pumps start surging, Led flickers and it burns out going normally closed shorted and pumps run til the battery is disconnected. Pulled it apart and the diode is burnt out. 

Relay is the typical 100A item in the diagram above, running 2x Walbro 460 fuel pumps. 

Link output to the negative terminal of control side is set to Fuel pump speed as advised. 

 

Any clues? 

[Ducie54]

What part number ssr? Note there are AC and DC relays. I'm using 3 currently wired like the last pic for water pumps and 2nd Bosch fuel pump.

 

What's the setting in FP speed? 

Edited August 1, 2017 by Ducie54

[Benny]

Standard 3-32VDC control.
Part number: SSR-D06100D

The 12v switched power to the control side was looped out of the lift pump relay when the ECU pulled that in.
The PWM control was set to

FP Speed
100Hz
Low Polarity and Driver

The Fuel Pump Speed table was set to 30% at idle IDC.

[Ducie54]

What are the settings in the fuel pump control tab? There should be offset and multiply values.

I would start by changing from fp speed to a GP output. Make sure it works without faulting. Change to to GP pwm next. See how that goes. 

[MagicMike]

Bumping this up...

 

I have recently changed my fuel setup from big (useless) fuelab pump on a surgetank, to 2 x walbro 460's in tank.

Initially they are staged, and working as expected, but the fuel (and differential) pressure increases more than I would like with the 2nd pump on (between 25 and 30kpa).

Long term, I am concerned about having 1 pump dormant majority of the time, so I would like to run them together, but this comes with the downside of increased fuel flow (heat, which I have had issues with).

So, I would like to try the SSR method of PWM control on both pumps together. Looking for advice on how to wire this up, understanding that factory fuel pump relay needs to remain as master on/off control (rpm=0=pumps off).

Can I have the OE fuel pump relay control feed Pin 2 in this diagram?

Both pumps earthed directly to battery.

I also need to ask about the use of the diode, and if it is required, and if so, how to know which one and where to put it?

[Adamw]

Ideally the ECU aux will be connected to the -ve terminal (terminal 4 in your photo) assuming the relay can work that way.  Pin three would then just be ign switched +12V.  Set the ECU aux up as "FP Speed" and set it to open loop mode.  The ecu will then still take care of the prime and "rpm=0=pumps off".  You will not need the original FP relay to do this.

If your relay datasheet states it is suitable for inductive loads then you will not need a diode. If it is not designed for inductive loads then you will need to seek the suppliers advice on a suitable diode. 

Edited September 28, 2017 by Adamw

[MagicMike]

Ideally the ECU aux will be connected to the -ve terminal (terminal 4 in your photo) assuming the relay can work that way.  Pin three would then just be ign switched +12V.  Set the ECU aux up as "FP Speed" and set it to open loop mode.  The ecu will then still take care of the prime and "rpm=0=pumps off".  You will not need the original FP relay to do this.

If your relay datasheet states it is suitable for inductive loads then you will not need a diode. If it is not designed for inductive loads then you will need to seek the suppliers advice on a suitable diode. 

Thanks Adam. The SSR I have is the one from Jaycar in the original post in this thread.

What I took from your post, is that the trigger for the relay should be as per Ducie's last diagram, which I have modified below. Any issues with this?

 

Actually, Ducie's last diagram is why I asked about the diode, as it is not in his final, but was in the earlier ones.

Edited September 28, 2017 by MagicMike

[Adamw]

Their datasheet doesnt seem to match their description.

It says to refer to the datasheet, but the datasheet doesnt show any diagram and also doesnt have "precaution 1,2,3 etc"

 

 

 

So I would use something like a 1N4004 and wire it across the motor like this:

Edited September 28, 2017 by Adamw

[KYPREO]

Bumping this thread. The Haltech SSR is essentially the same as the Jaycar relay listed above. It does not have an internal flyback suppression and so will need a diode to be fitted across the load if the device uses a bit of current (like a fan).  Also, Haltech latest revision of the instruction manual shows a different wiring diagram for ground switching a device than those listed above, with the +ve terminal of the load wired directly to battery +ve (although I think this should have a fuse), and the +3 terminal of the SSR connected to switched ignition +ve (which I think should come from the relay output after the main ECU relay so as to avoid backfeeding).

Unlike the Haltech, the Link does not need a pullup resistor across the SSR.

Based on the above factors, I am thinking the wiring for the Jaycar/Haltech SSR on a Link should look something like this (with flyback diode, eg 1N4004, wired across the load):

 

[Adamw]

It will work fine as you have drawn it or as Ducie has drawn it.  My understanding of the flyback diode is it needs to be rated for the same current as the motor would normally pull and a common rule is at least 5x the normal working voltage, a 1N4004 meets the voltage requirement but is only rated for 1A.

[KYPREO]

15 hours ago, Adamw said:

It will work fine as you have drawn it or as Ducie has drawn it.  My understanding of the flyback diode is it needs to be rated for the same current as the motor would normally pull and a common rule is at least 5x the normal working voltage, a 1N4004 meets the voltage requirement but is only rated for 1A.

Thanks Adam.

The IN4004 has an average forward current rating of 1A but a non-repetitive forward surge current rating of 30A.  When used as a flyback diode, I imagine current wouldn't be flowing through the diode long enough for the forward average current to matter much..it's more the temporary spike from the inductive discharge from the motor when switched off between cycles?  Assuming that is correct, the 30A is still probably insufficient for my particular application. While enough for my fan at full load (~26A) is not enough for inrush current, which is around 5x that, so the diode should be able to handle 150A to be on the safe side.

You can get fast switching Schottky rectifiers in the DO-201AD size with 5A forward current rating and up to 220A non-repetitive forward surge current rating. Something like Vishay SB-560 which is rated at 60V and 220A and looks quite cheap. The Schottky rectifier is probably more suitable to high frequency switching than the 1N400x diodes anyway.

The D0-201AD package is the style of diode recommended by Power-Io who makes high current solid state relays for DC usage (see https://www.power-io.com/products/hdd.htm)

Any thoughts appreciated

[Adamw]

I only have a basic understanding of this type of thing and have never had to research it much so I will just give my thoughts...

6 hours ago, KYPREO said:

When used as a flyback diode, I imagine current wouldn't be flowing through the diode long enough for the forward average current to matter much..it's more the temporary spike from the inductive discharge from the motor when switched off between cycles?  Assuming that is correct, the 30A is still probably insufficient for my particular application. While enough for my fan at full load (~26A) is not enough for inrush current, which is around 5x that, so the diode should be able to handle 150A to be on the safe side.

Inductors try to resist current change.  When power to an inductor is suddenly switched off, the inductor will try to maintain the current flow at the same level it was.  So you dont need to allow for inrush etc.  If the motor was pulling 20A when the power was switched "off", the inductor would try to keep pushing 20A around the circuit (diode).  

PWM throws a whole lot more complication into it as you still need it to "turn off" quickly.  This is where my experience is lacking, those relays above from what I hear dont work much above about 100Hz anyway so it shouldnt be too difficult.  If you can find a Schottky with a high enough reverse voltage (60V+) I would lean towards that option. 

[Manuel]

Hello
I also have a problem with my ssr,
Have all the cabling you've tested, whether Low Side Driver or High Side Driver, just do not get it to work.
synonymous have a 1N4004 diode installed.

My problem is when I start the vehicle, the system runs for a short time after that the relay switches off for about half a second and then goes back in, which happens every two to five seconds.

used pump original bosch 044
Tested relay once 60amper china
and once crydom 12A

the technical data sheet from china ssr looks like this
      One-off time: ≤10ms
      Control current: 5-25mA DC
      Dielectrics voltage-resistance: 2500VAC
       Environment temperature: -30 ℃ - + 75 ℃
      Working indicator: LED

can it be the control current is too high and I have to install a resistance?

Thank you for your help in advance