Live continuity test - Electric shower

[Tommy87]

Hello,

I have a triton spellbind shower that is giving me jip. It will run for a couple minutes and then give me a "low pressure" fault. I contacted Triton and was advised to check the solenoid coil, I did this and got a resistence of 3.5k/ohms which seems OK. I now have to conduct a live continutiy test. I'm OK with electrics I have fault diagnosed and replaced parts on this shower before as well as electric storage heaters but a live continuity test seems a bit sketchy. Tritons terribly meta message e-mails aren't much help -

"With regards for continuity to the solenoid valve we need to check from the terminal block on the shower to the solenoid. With the previously carried out resistance check we have already established that the solenoid coil is working, we now need to establish if the power (at a full 230 / 240v) is present to the solenoid valve to allow it to work."

I believe I should conduct a continuity test from the neutral of the terminal block to the neutral of the solenoid valve. Is this correct?

My super handy multimeter doesn't have a continuity tester, can I just set my meter to resistance and test it? If there's continuity I'll get a reading if not there'll be infinite resistance? I have done this before but never on a LIVE system which is causing my doubts.

Thanking you in advance

 

[ericmark]

Have you tested the water supply? I found my shower doing odd things due simply to stop tap not being fully open.

It would seem they suspect the solenoid is not fully opening, to test would mean exposing live parts which in a bathroom full of water is not really the way to work. If there is a voltage reduction then the amps drawn will be reduced so I would use a clamp on ammeter to see if drawing full current what could be done well away from water.

However much is down to what test equipment you have. Using a loop impedance tester you can test supply without turning on the shower. A multi-meter has limitations.

I would suggest turn shower to cold and fill a gallon bucket while timing how long. The shower details will say how much water per minute it requires. Measuring how much water per minute is far safer than trying to measure voltage on a solenoid.

 

[ban-all-sheds]

a live continuity test seems a bit sketchy.

There's no such thing.

Continuity exists (or not) whether the circuit is live or not.

I believe I should conduct a continuity test from the neutral of the terminal block to the neutral of the solenoid valve. Is this correct?

Why do that?

And why only N?

Why not just measure the voltage present at the solenoid?

My super handy multimeter doesn't have a continuity tester, can I just set my meter to resistance and test it? If there's continuity I'll get a reading if not there'll be infinite resistance? I have done this before but never on a LIVE system which is causing my doubts.

If you connect a meter on a resistance setting into a live circuit, be prepared for the possibilities of very spectacular results and a need for medical treatment.

TBH I don't think you should be poking around inside a powered appliance.

 

[bernardgreen]

TBH I don't think you should be poking around inside a powered appliance.

I totally agree with that.

"Live continuity" testing is using a VOLTMETER to look for potential differences between two points that should be connected together. If there is no voltage difference then the circuit between them is continuous. Becuase this will also show a false continuity if there is no power on the circuit then with the power removed a resistive continuity check is also needed. Live continuity would not be necessary on a shower. The few times it is neccesary is when relays or other electrically operated switches are part of the circuit being tested for continuity. These may be operating incorrectly when the system is powered up.

The DC resistance of a solenoid coil is not a valid indication of it being a good coil. One shorted turn in the coil will reduce its magnetic force, ( so it doesn't operate properly ), and also cause heating in the coil. The DC resistance will not change much due to a few shorted turns

 

[Tommy87]

Eric thank you very much for the rapid response, I do appreciate it. I have tested the water pressure and it was giving me 1.5/2 bar, which I think is fine, there were times when it was running OK when I'd get low pressure fault which I believed was genuine as I'm on the top floor so I don't really have the option to shower in the morning. I only have a multimeter I'm afraid.

The guy from Triton was insistent that I need to do a "LIVE continuity test". Below is team Tritons response....

"In simple terms we need to establish of power at a full 230 / 240v is reaching the solenoid valve. The logic here being that if it is and the solenoid is operating correctly then water should flow through the shower.

As water is not flowing when the fault is present we know that either the solenoid is failing or there is no or insufficient power reaching the solenoid valve.

With the Cover not connected this would be like having the unit in it's commissioning mode which should still allow power to reach the solenoid valve and the solenoid valve to open. It may be that the works OK in this situation and only shows the fault when the Cover is connected depending on the results this will help ID if Solenoid Valve, Cover PCB or Power PCB."

Ban all sheds - Thank you for the straight shooting. To measure the voltage at the solenoid would that be from the terminal box to the solenoid? Or simply across the solenoid?

Bernard - Thank you for that information Re. the solenoid valve and the limitations of a simple resistance check.

What I think i'm going to do is buy a new solenoid coil, it costs £10. Any other test will only highlight a failed PCB which is not going to be economical to fix anyway. If the new coil works good times, if not well I've wasted £10, does this seem like a reasonable plan of attack?

Thank you again for all your advice.

 

[EFLImpudence]

The guy from Triton was insistent that I need to do a "LIVE continuity test".

Did he not mean do a continuity test on the live (line) conductor; not do it while live?

 

[Tommy87]

The guy from Triton was insistent that I need to do a "LIVE continuity test".

Did he not mean do a continuity test on the live (line) conductor; not do it while live?

He did not, snippets from his e-mails;

"A continuity check to the solenoid valve assy could also be actioned. This would need to be actioned at the time that the fault is present." - How can the fault be present when it's not on?

"In order to check the continuity to the solenoid valve this would need to be undertaken as a LIVE check."

"In simple terms we need to establish of power at a full 230 / 240v is reaching the solenoid valve. The logic here being that if it is and the solenoid is operating correctly then water should flow through the shower.

As water is not flowing when the fault is present we know that either the solenoid is failing or there is no or insufficient power reaching the solenoid valve.

With the Cover not connected this would be like having the unit in it's commissioning mode which should still allow power to reach the solenoid valve and the solenoid valve to open. It may be that the works OK in this situation and only shows the fault when the Cover is connected depending on the results this will help ID if Solenoid Valve, Cover PCB or Power PCB."

 

[JohnW2]

The guy from Triton was insistent that I need to do a "LIVE continuity test".

Did he not mean do a continuity test on the live (line) conductor; not do it while live?

Fair enough. It sounds that, in fact, the only incorrect/confusing thing he said/wrote was to use the term "continuity test" when he was actually talking about (necessarily 'live') voltage measurements.

Kind Regards, John