Ssvr troubleshooting

[Stephen J Blake Jr]

Link Posted: Mon Nov 20, 2017 12:33 am Post subject: SSVR Troubleshooting
Hello,

I have rigged up a simple boil controller, under the guidance of my friend who is a former electrician apprentice.

I have an Auber 25A SSVR with rheastat and heatsink, powering a 5500W element, housed in a BrewHardware HotRod, and activated/deactivated by a Siemens 30A knife switch box, with power originating at a 50A GFCI breaker in the home's main panel.

A Couple points of concern:
-The output voltage from the SSVR does not change from 120V no matter the setting on the rheastat. I am not convinced that it is functioning.
-The heatsink grows quite hot (perhaps 140*F or more)

I assume that the SSVR regulates output voltage, and that the reading on the output terminal should decrease with respect to knob position. Is this incorrect? What could be wrong here?

I also worry about the amount of heat being generated. What are normal operating temperatures for this heatsink and SSVR combo?

Am I missing something? I have rheastat leads two and three hooked to the SSVR as directed in Auber's documentation. One leg of power is regulated through the SSVR, while the other is always on, unless the knife switch is thrown.

 

[shoo]

Gonna have to be WAY more specific. Can you draw out exactly as you have everything wired? How are you reading the voltage? What specific SSVR? Are you absolutely sure you have it wired right (pictures would help)?

 

[processhead]

A more accurate way to tell if your SSVR is working correctly is to measure the AC current while adjusting the control through its operating range. Ask your former apprentice buddy if he still has a clamp on ammeter and how to operate it safely.

The AC current should increase and decrease smoothly as the control knob is turned clockwise and counter clockwise.

If you are operating the system on 240 volts, the current should measure very close to 23 amps at a full clockwise setting of the control.
This is also close to the max amp rating of your SSVR and it will get fairly warm.

 

[Stephen J Blake Jr]

A more accurate way to tell if your SSVR is working correctly is to measure the AC current while adjusting the control through its operating range. Ask your former apprentice buddy if he still has a clamp on ammeter and how to operate it safely.

The AC current should increase and decrease smoothly as the control knob is turned clockwise and counter clockwise.

If you are operating the system on 240 volts, the current should measure very close to 23 amps at a full clockwise setting of the control.
This is also close to the max amp rating of your SSVR and it will get fairly warm.

This is to say that the output voltage from the ssvr could be 120v despite being regulated down?

 

[processhead]

This is to say that the output voltage from the ssvr could be 120v despite being regulated down?

The voltage from the output of an SSVR is a non-sinusoidal waveform. This means some meters may misread the voltage and mislead you at anything other than full-on power setting.

Are you operating this element on 240 volts or 120 volt input power to the SSVR?

 

[Stephen J Blake Jr]

The

The voltage from the output of an SSVR is a non-sinusoidal waveform. This means some meters may misread the voltage and mislead you at anything other than full-on power setting.

Are you operating this element on 240 volts or 120 volt input power to the SSVR?

One hot leg goes through the ssvr while the other hot goes directly into the element. This is how the auber diagram shows the 240v setup. Is this incorrect?

 

[processhead]

Your description sounds like it is wired right for 240 volt operation.

 

[Stephen J Blake Jr]

Did a boil test on 7.5 gallons. Boils intensity unchanged from min and max settings. Ssvr is providing max power at any setting. 1400w (approx wattage of element run on one leg) should not boil 7.5 gallons so aggressively, i should think.

 

[Stephen J Blake Jr]

Did a boil test on 7.5 gallons. Boils intensity unchanged from min and max settings. Ssvr is providing max power at any setting. 1400w (approx wattage of element run on one leg) should not boil 7.5 gallons so aggressively, i should think.

 

[processhead]

From your description, it sounded like the pot was connected correctly to the SSVR. You may want to double check your wiring one more time, though.
It is possible your SSVR has a shorted output, but you may want to check the rheostat first. It should measure 20,000 ohms at maximum and reduce to near zero at its minimum setting.
You can test it with a multimeter set to measure ohms.

 

[doug293cz]

From your description, it sounded like the pot was connected correctly to the SSVR. You may want to double check your wiring one more time, though.
It is possible your SSVR has a shorted output, but you may want to check the rheostat first. It should measure 20,000 ohms at maximum and reduce to near zero at its minimum setting.
You can test it with a multimeter set to measure ohms.

Disconnect all power before checking the resistance of the potentiometer. There is line voltage on the potentiometer when in operation. This can damage the multimeter, and shock you as well.

Brew on

 

[doug293cz]

Are you testing the voltage with the element connected or disconnected? SSVR's (like SSR's) have a leakage current that is non-trivial, and will cause a high impedance meter (most modern meters) to measure the full line voltage no matter how it is switching.

Also, which two terminals of the potentiometer are connected to the SSVR? A pic would be good.

Brew on

 

[Stephen J Blake Jr]

Quite sure i have a shorted ssvr. Ordered s new one from auber. Pot was reading 0-20kohm

 

[processhead]

^^^ Agree. Some good photos showing how things are connected would be helpful. Verbal descriptions of your panel don't help us to help you find errors in wiring or other problems.

 

[Stephen J Blake Jr]

The SSVR was indeed fried. After installing my new one, everything is functioning normally.

I do wonder how hot this heat sink should be, however. Is it normal for it to excede 140 degrees or so? I have the recommended heatsink for Auber's 25A SSVR.

 

[The_Bishop]

Because you are running right at the maximum rating of the SSVR, it's going to get hot.

 

[ancientmariner52]

Did you use any thermal paste between the save and heat sink? It really helps.

SSVR. And I can't even blame auto correct.

 

[doug293cz]

The SSVR was indeed fried. After installing my new one, everything is functioning normally.

I do wonder how hot this heat sink should be, however. Is it normal for it to excede 140 degrees or so? I have the recommended heatsink for Auber's 25A SSVR.

I believe 140°F (60°C) is the upper acceptable operating temp limit. It would be better to be operating cooler (fan, bigger HS.)

Brew on

 

[Stephen J Blake Jr]

Definitely used the grease provided with the heat sink. Thin layer across the metal interface of the ssvr.

I will try to throw a fan on there. Best way to rig an old mini molex fan to AC power from my box?

 

[doug293cz]

Definitely used the grease provided with the heat sink. Thin layer across the metal interface of the ssvr.

I will try to throw a fan on there. Best way to rig an old mini molex fan to AC power from my box?

A small AC fan can be a simple solution, as it doesn't require you to add a DC power supply.

Can you post some pics of your system? Then we can look for possible physical configuration issues.

Brew on