Pete Zahut wrote:
> Wife was in the shower this morning when it stopped working. Went down to
> the consumer unit to discover that it hadn't tripped it's own individual MCB
> but it had tripped the 30mA RCD - reset RCD and all other circuits fed by it
> are fine; shower solenoid valve operates so that we now get water flow but
> water doesn't heat up at all.
Chances are the heating element has failed, and for a brief time at
least was causing a live to earth short.
Triton pressure relief device (PRD) 82800450. August 2018: The old, cream coloured PRD with a black rubber ball has now been replaced with a black version and membrane. The functionality remains the same as before. A pressure relief device (PRD) is a safety device in electric showers. If water is unable to exit through the shower head, an. In this episode, George talks us through replacing a Pressure Relief Device (part no.82800450) on a Triton T80Z electric shower. Buy this spare part on The S.
> First point - I know that there is a thermal cutout but can't see any
> obvious signs that it has operated, nor any obvious means to reset it if it
> has - or is it a self-resetting device, ie, does it operate until the
> temperature drops down to safe levels and then reset itself? Any way of
> testing these?
Don't know, but it should be easy enough to test...
> Second point - Would a thermal cutout problem trip the RCD? I'm no
Its unlikely...
> electrician by any means but my very limited knowledge of RCDs and the way
> they sense imbalances is sort of pointing me towards a possible heating
> element failure, ie, element casing fails and water gets into
> lecktrickery-carrying parts allowing current to leak to earth, thereby
> tripping the RCD.
Indeed - far more probable.
> I suppose this is easy enough to test for by connecting a multimeter between
> the copper body of the heater can assembly and the heating element
> terminals, but what sort of values would indicate a faulty/non-faulty
> condition?
Firstly what is the state now? Does the shower work at all (i.e. does
the solenoid still work and water flow (albeit cold))?
There are a few tests you can do....
(Obviously make sure the shower is isolated from the mains before going
any further)
Referring to the parts diagram here:
Triton T80xr Low Pressure Gauges
see if you can take a measurement between the contacts on the thermal
cutout. Using a low resistance range, you should see a resistance of to
all intents and purposes zero. If it is open circuit then there is one
failure. However It would be wise to attempt to work out why it cutout
rather than just replacing it.
Next measure between the two ends of the heating element. You should see
a low but non zero resistance. Say your shower is a 9.5kW one this would
be something like 240^2 / 240 or about 6 ohms. If it is significantly
higher than this then that suggests an element failure.
Now using your highest resistance range measure between both ends of the
heater terminals and the earth conductor. You should see an open circuit
here or at least a very high resistance >= 2MOhms. (note this is not a
definitive test, in that there are cases where the breakdown of the
insulation is only evident at much higher voltages that a standard
multimeter is capable of testing at)
> Could it be something else entirely?
Check power is reaching the shower in the first place - its indicator
lights come on etc.
--
Cheers,
Triton T80xr Low Pressure Relief Valve
John.
Triton T80xr Low Pressure Washers
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