Hello all,
I have a 20gpm pump for a big caravan for shower use etc. It's great but the included relay for the pressure is clicking on and off constantly, after a few mins it overheats and stops working. What options do I have to replace it?
I'm tempted by mosphets, solid state relays, heavy duty relays (for starter motors etc) but looking for something that actually is just able to be switched on and off really often without overheating, any ideas?
Thanks

 

The On/Off constant clicking is a symptom unless it is supposed to be doing that. The question is why it constantly turns on and off? What is getting hot, the relay coil or the contacts? A relay coil designed for sustained use should not overheat.

With a known coil voltage yes, you can replace the relay with a solid state DC relay or MOSFET circuit. I would, however, try and find the cause of it getting hot. Part numbers and load data would help?

Ron

 

The On/Off constant clicking is a symptom unless it is supposed to be doing that. The question is why it constantly turns on and off? What is getting hot, the relay coil or the contacts? A relay coil designed for sustained use should not overheat.

With a known coil voltage yes, you can replace the relay with a solid state DC relay or MOSFET circuit. I would, however, try and find the cause of it getting hot. Part numbers and load data would help?

Ron

I would put it's reason down for getting hot is the spark from the high amperage, it's direct (with a fuse) to a leisure battery, so it must be consuming a lot of amps.

It's clicking on and off correctly, it's the pressure switch. Was just hoping there's a better solution than a physical contact clicking on and off quite rapidly.
I'll look up the model number and current draw now

 

What is the part number of the relay?
Symptoms such as that indicate either the wrong coil data or the wrong voltage.
Max.

 

The relay coil should not switch on and off if the relay contacts are conducting high current, unless the load is dropping the voltage somehow.
Max.

 

https://www.amazon.co.uk/dp/B01M5AYV19/ref=cm_sw_r_cp_apa_fabc_QJ56HRM0Q4T9G8GNSWGD

Looking at the third photo you can see the pressure switch on the front with the red wires leading to the relay on the left side. That's all.

 

What is the relay data?
Max.

 

The relay coil should not switch on and off if the relay contacts are conducting high current, unless the load is dropping the voltage somehow.
Max.

As it's a water pump with a pressure switch I believe it's working normally as it should, it's just as you use the pump especially not at full flow it's reaching max pressure quickly so the pressure relay is clicking on and off really fast to keep up, causing the sparks to make it overheat

 

According to the Ad the pump comes in LV DC and 220AC?
Did you supply the relay or is it built in?
I see by the title it is 12vdc.
Max.

 

According to the Ad the pump comes in LV DC and 220AC?
Did you supply the relay or is it built in?
I see by the title it is 12vdc.
Max.

Supplied and built in. Standard 30a 12v automotive relay. It doesn't run on 220v it's a direct 12v pump

 

I've dug out the old footage of me installing it (van is not currently with me, it belongs to my sister who is having issues)
Listen to that relay clicking away as the pressure rises and drops:
https://photos.app.goo.gl/XXdhzXmc9XQqaXEG8

 

If the relay is clicking on and off rapidly to maintain the pressure, then it would seem you need a small pressure tank (one with an air bladder) to store pressurized water for a period of time.
Depending upon the size of the tank, that should greatly reduce the on/off cycling.

 

Hello,

@crutschow , I think you mean an expantion vessel:
expantion vessel

Bertus