hot tub fault tripping after switching on

[marc8]

installed a tub for m8 (second hand).

switch on tub runs for about 10 seconds then trips.

clamped up draw initially 3.3A -12.2A when heater kicks in.

disconnected heater unit IR test 400M ohms, 23 ohms heater resistance.

disconnect pump one hot tub will stay on, disconnect heater & leave pump one on hot tub will run but did trip once after about 20 mins.

pump one
checked capacitors 16m farad good, 40m farad good. checked windings brown to blue 11.08 ohms, black to blue 11.10 ohms. IR test to earth 400M ohms.

disconnect plugs for ozone still trips, blower still trips & light still trips.

my findings hot tub turns on timer runs down pump one starts draw around 3amps heater kicks in around 12amps then trips after about 2-3 seconds later thinking I have a earth fault under load or am I missing something ?

 

[Wilko]

Guessing it's the 30mA RCD that trips - ramp test it? Measure the earth leakage at the tub. When heater IR tests were done, was the tub in working condition with water etc. Results so far seem to point to heater, but that's not backed up by the IR test . What is the earthing arrangement (just interested) and has the tub been working ok for a while, or is this maybe why the previous owner sold it on?

 

[Pete999]

installed a tub for m8 (second hand).

switch on tub runs for about 10 seconds then trips.

clamped up draw initially 3.3A -12.2A when heater kicks in.

disconnected heater unit IR test 400M ohms, 23 ohms heater resistance.

disconnect pump one hot tub will stay on, disconnect heater & leave pump one on hot tub will run but did trip once after about 20 mins.

pump one
checked capacitors 16m farad good, 40m farad good. checked windings brown to blue 11.08 ohms, black to blue 11.10 ohms. IR test to earth 400M ohms.

disconnect plugs for ozone still trips, blower still trips & light still trips.

my findings hot tub turns on timer runs down pump one starts draw around 3amps heater kicks in around 12amps then trips after about 2-3 seconds later thinking I have a earth fault under load or am I missing something ?

Well if you are getting those sort of insulation resistance readings it no wonder the tub is tripping out. What is actually tripping CB or RCD?

 

[Andy-1960]

What is the size and type of breaker that is tripping?

 

[marc8]

Hi Pete
VIR
230 V
10.3 I
23.3 R
sorry am I having a blond moment heater is 2.5kw.

400M ohms IR test to earth good
23.3 ohms heater continuity

 

[marc8]

Hi Andy-1960

b32 amp
RCD unit is tripping

 

[Pete999]

VIR
230 V
10.3 I
23.3 R
sorry am I having a blond moment heater is 2.5kw.

400M ohms IR test to earth good
23.3 ohms heater continuity

Whats tripping cb or RCD?

 

[marc8]

Guessing it's the 30mA RCD that trips - ramp test it? Measure the earth leakage at the tub. When heater IR tests were done, was the tub in working condition with water etc. Results so far seem to point to heater, but that's not backed up by the IR test . What is the earthing arrangement (just interested) and has the tub been working ok for a while, or is this maybe why the previous owner sold it on?

good idea I will ramp test RCD & check the leakage of the trip with tub on & see the spike. will check Monday, did not think RCD as know the house no issues with RCD to date. TNCS

 

[marc8]

Whats tripping cb or RCD?

RCD

 

[marc8]

my thoughts at guess at one point heater had small crack in when heating let water past but heater has water around it all the time so can't see it especially with the IR value being good.

 

[marc8]

Well if you are getting those sort of insulation resistance readings it no wonder the tub is tripping out. What is actually tripping CB or RCD?

Hi Pete
VIR
230 V
10.3 I
23.3 R
sorry am I having a blond moment heater is 2.5kw.

400M ohms IR test to earth good
23.3 ohms heater continuity
did you spot something that in the above that I may have missed ?

 

[Wilko]

good idea I will ramp test RCD & check the leakage of the trip with tub on & see the spike. will check Monday, did not think RCD as know the house no issues with RCD to date. TNCS

Hi - understand, I have seen where RCD is a bit sensitive and a few mA is already there from other appliances on the circuit (?).

 

[Specialist]

Just a thought: Have you IR tested the element when it's hot ?.

 

[marc8]

Just a thought: Have you IR tested the element when it's hot ?.

I will have to disconnect from tub connect heater turn on without tub being connected & heat the thing up & see what happens. good idea will try Monday

 

[marc8]

Hi - understand, I have seen where RCD is a bit sensitive and a few mA is already there from other appliances on the circuit (?).

be quite honest there is only 3 items on this side of the board & hardly any equipment installed apart from usual fridge wash machine few sockets, not really much in Bungi