Trouble with SSR

[tucker0104]

I had a SSR and a potentiometer in a old plastic box and just upgraded to a nice project box. Unfortunately took me over a year to do because of lack of free time. It is a 40 amp relay with 500K pot and a 22 amp max heater. The problem I am having is that the smallest turn down from maximum on the pot turns the SSR off completely. So, I was wondering if anyone else had run into this. I've done a little troubleshooting of a loose connection at the pot and going to do some more but how do you tell if you have a bad SSR. I used the ohm meter on the pot and it reads from 0 to 500K so that is working. Any ideas?

[Pikey]

Sorry I think we need to see your circuit diagram and know what you mean by an "SSR" - 500k pot sounds bloody big to me tho' depending on the inter-relationship with the rest of the components.

[tucker0104]

Solid state relay. I pot gates more or less voltage if you turn it up or down.

https://en.wikipedia.org/wiki/Solid-state_relay" onclick="window.open(this.href);return false;" rel="nofollow

[shadylane]

Is the heater connected during the test
Also if the SSVR is running on 120v the pot needs to be 250k

[Pikey]

Solid state relay. I pot gates more or less voltage if you turn it up or down.

https://en.wikipedia.org/wiki/Solid-state_relay" onclick="window.open(this.href);return false;" rel="nofollow

Possibly - depending on what exactly you have it hooked up in parallel with

And of course exactly where you are getting your trigger voltage from.

Thank you for that wikipedia post -

No wonder people are flailing in the dark !

[shadylane]

I've done a little troubleshooting of a loose connection at the pot and going to do some more but how do you tell if you have a bad SSR. I used the ohm meter on the pot and it reads from 0 to 500K so that is working. Any ideas?

With the power off and the pot wired in, check the resistance between pins 3 and 4 on the SSVR while varying the pot

[tucker0104]

I've done a little troubleshooting of a loose connection at the pot and going to do some more but how do you tell if you have a bad SSR. I used the ohm meter on the pot and it reads from 0 to 500K so that is working. Any ideas?

With the power off and the pot wired in, check the resistance between pins 3 and 4 on the SSVR while varying the pot

Thanks for the reply. It is 240V. When connected to the SSR pins, it reads the maximum 500K and I think 0 ohms. Not sure on the minimum. It almost seems like a problem with the SSR. It works on maximum and a little lower but then goes to 0 voltage.

[tucker0104]

Solid state relay. I pot gates more or less voltage if you turn it up or down.

https://en.wikipedia.org/wiki/Solid-state_relay" onclick="window.open(this.href);return false;" rel="nofollow

Possibly - depending on what exactly you have it hooked up in parallel with

And of course exactly where you are getting your trigger voltage from.

Thank you for that wikipedia post -

No wonder people are flailing in the dark !

Thanks for the valuable input. If you wanted specific information then feel free to ask specific questions.

[shadylane]

It almost seems like a problem with the SSR.

Seems like it to me also, do you have a spare SSVR in your pocket for trial by substitution

[tucker0104]

It almost seems like a problem with the SSR.

Seems like it to me also, do you have a spare SSVR in your pocket for trial by substitution

I wish I did. I had to do a run at almost full speed today. Still have another run to do but it can wait for me to get a new one. I went ahead and ordered a new SSR and pot so that should take care of any issues. Thanks again for the help.

[shadylane]

Should have ordered two of them
Don't forget the thermal paste

[6 Row Joe]

Something doesn't sound right here. From what I understand a SSR is a on/off switch. It doesn't have variable output. Your Pot is a variable resistor and if large enough doesn't need a relay. If you use a PID controller, it monitors the temperature and controls the output current by pulsing the relay. I don't understand how a potentiometer could control a solid state relay. You need a controller that can turn the SSR on and off.

[tucker0104]

Something doesn't sound right here. From what I understand a SSR is a on/off switch. It doesn't have variable output. Your Pot is a variable resistor and if large enough doesn't need a relay. If you use a PID controller, it monitors the temperature and controls the output current by pulsing the relay. I don't understand how a potentiometer could control a solid state relay. You need a controller that can turn the SSR on and off.

PID is a bad idea because your temperature of your boil changes as the alcohol content changes. An SCR can use an outside signal to control the peak voltages of the input for the heater essentially lowering the input voltage. So, you can have a pot that can control the amount of heat you want to add or take away.

[slowpoke]

I made myself a adapter cable so I can keep runnin if my controller goes bad. Its a 3 prong 120v plug on one end and a L6-30R on the other end. I can plug directly to a 120v outlet if need be and keep on runnin. The power to the element is a lot lower and its low enough for even a spirit run. Used it onest and got me through the run in a pinch.

[Pikey]

Solid state relay. I pot gates more or less voltage if you turn it up or down.

https://en.wikipedia.org/wiki/Solid-state_relay" onclick="window.open(this.href);return false;" rel="nofollow

Possibly - depending on what exactly you have it hooked up in parallel with

And of course exactly where you are getting your trigger voltage from.

Thank you for that wikipedia post -

No wonder people are flailing in the dark !

Thanks for the valuable input. If you wanted specific information then feel free to ask specific questions.

I did !

Sorry I think we need to see your circuit diagram and know what you mean by an "SSR" - 500k pot sounds bloody big to me tho' depending on the inter-relationship with the rest of the components.

[Pikey]

Thanks for the reply. It is 240V. When connected to the SSR pins, it reads the maximum 500K and I think 0 ohms. Not sure on the minimum. It almost seems like a problem with the SSR. It works on maximum and a little lower but then goes to 0 voltage.

No - If it does full conduction and zero, the Semiconductor element is working - it is a "Silicon Controlled Rectifier" - or "Solid State Relay" ??? - ie a simple switch, controlled in one way or another by a gate voltage.

Your variable resistance (0-500k) allows a current to pass through and that current charges a capacitor. When teh charge on the capacitor reaches the gate voltage, the gate opens and lets current flow through the "Relay" - If you show us your circuit, we may be able to help.

Otherwise - pages 4,5,6 here can give you some ideas perhaps ?

https://www.littelfuse.com/~/media/elec ... te.pdf.pdf

[6 Row Joe]

Thanks for the reply. It is 240V. When connected to the SSR pins, it reads the maximum 500K and I think 0 ohms. Not sure on the minimum. It almost seems like a problem with the SSR. It works on maximum and a little lower but then goes to 0 voltage.

No - If it does full conduction and zero, the Semiconductor element is working - it is a "Silicon Controlled Rectifier" - or "Solid State Relay" ??? - ie a simple switch, controlled in one way or another by a gate voltage.

Your variable resistance (0-500k) allows a current to pass through and that current charges a capacitor. When teh charge on the capacitor reaches the gate voltage, the gate opens and lets current flow through the "Relay" - If you show us your circuit, we may be able to help.

Otherwise - pages 4,5,6 here can give you some ideas perhaps ?

https://www.littelfuse.com/~/media/elec ... te.pdf.pdf

My thoughts exactly. A SSR and a SCR are 2 different relays.

[shadylane]

Sorry I think we need to see your circuit diagram and know what you mean by an "SSR" - 500k pot sounds bloody big to me tho' depending on the inter-relationship with the rest of the components.

[sambedded]

Thanks for the valuable input. If you wanted specific information then feel free to ask specific questions.

Could you post a few pictures of your wiring?

[Yummyrum]

My question is : are you using the exact same bits that you used in your original controller ....that obviously worked Ok for you ...just a bit rough .

OR , have you bought some new components to build your new controller ?

My thinking here is perhaps you bought a new Pot and its a Logarithmic type "A" ....not a linear type "B" .....that could explain the sudden touchy full on down to off type control you now have .

Failing that , it would seem like your old SSR had shat itself although its quite strange . They are pretty robust devises and unlikely to be zapped by static or the likes due to simply removing and reassembling .

But thinking out aloud , perhaps internal damage may have happened due to physical things such as an internal electrical brake between the contact screws and the internal curcuit during unscrewing and tightening the new connections .

[Pikey]

My question is : are you using the exact same bits that you used in your original controller ....that obviously worked Ok for you ...just a bit rough .

OR , have you bought some new components to build your new controller ?

My thinking here is perhaps you bought a new Pot and its a Logarithmic type "A" ....not a linear type "B" .....that could explain the sudden touchy full on down to off type control you now have .

Failing that , it would seem like your old SSR had shat itself although its quite strange . They are pretty robust devises and unlikely to be zapped by static or the likes due to simply removing and reassembling .

But thinking out aloud , perhaps internal damage may have happened due to physical things such as an internal electrical brake between the contact screws and the internal curcuit during unscrewing and tightening the new connections .

I'd say that if it heats with minimum resistance - but drops out as soon as he turns the resistance up - either the pot is too high value - OR the capacitor has gone leaky ! {Electrolytics are renowned for this }

[sambedded]

I'd say that if it heats with minimum resistance - but drops out as soon as he turns the resistance up - either the pot is too high value - OR the capacitor has gone leaky ! {Electrolytics are renowned for this }

Regular SSVR as on the picture above doesn't have an electrolytic capacitor. Usually it has 100nF ceramic one.

[Pikey]

I'd say that if it heats with minimum resistance - but drops out as soon as he turns the resistance up - either the pot is too high value - OR the capacitor has gone leaky ! {Electrolytics are renowned for this }

Regular SSVR as on the picture above doesn't have an electrolytic capacitor. Usually it has 100nF ceramic one.

That's not shown in the picture tho' is it ?

Hence my request for the OP to show his wiring diagram !

[Edit - note also the VR values shown from 470R to 500,000 Ohms - lots of scope for experimentation there - dependingof course on teh values of the ther cmponents in the circuit ! ]

[sambedded]

That's not shown in the picture tho' is it ?

What's not shown in the picture? Capacitor? It's inside an SSVR. And you don't need any external one.

[Edit - note also the VR values shown from 470R to 500,000 Ohms - lots of scope for experimentation there - dependingof course on teh values of the ther cmponents in the circuit ! ]

This marking actually means 470KOhm-500KOhm

[Pikey]

This is the sort of stuff I use rather than making one up !

https://www.ebay.co.uk/itm/240V-AC-3800 ... rk:33:pf:0

But 3800 watts is not enough safety factor - it will blow on continuous usage - I use 10,000 watt units - but they only pop up when they do !

[sambedded]

SSVR it's exactly your controller where heatsink and pot should be connected external. SSVR just is more reliable and more suitable for industrial use.