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 ?

 

[Specialist]

Had a similar problem on a Sauna some years ago, IR test all good but within seconds of the heaters kicking in the RCD would kick out.
Turned out that it had been sitting in a warehouse unused for a while & the elements had got damp in them.

 

[marc8]

Had a similar problem on a Sauna some years ago, IR test all good but within seconds of the heaters kicking in the RCD would kick out.
Turned out that it had been sitting in a warehouse unused for a while & the elements had got damp in them.

Hi Thanks for that specialist
as above I will disconnect heater & power supply from tub probably use a 16amp CB inline at tub whilst I am there disconnecting & then turn on heater direct through 16amp CB, hopefully will trip or heat up.

 

[Specialist]

No probs & good luck.

 

[ruston]

Sorry if I have not read this properly , but is the supply new and tested out ok?

 

[marc8]

Sorry if I have not read this properly , but is the supply new and tested out ok?

yep

 

[ruston]

Sorry for asking the obvious, you never know when you might get a dodgy one.

 

[marc8]

Sorry for asking the obvious, you never know when you might get a dodgy one.

not a problem was worth a check, I had just run in the new supply myself & tested.

 

[seltechpc]

You could clamp the L and N and monitor till it trips, you can see leakage current start to rise at it heats up or the pump cuts in.

 

[LankyWill]

Could there be an issue with true earth and supplier earth? the leakage could be offsetting the RCD? We had to put an earth mat in when we installed one.

 

[Pete999]

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?

What 400 ohms

 

[Pete999]

What 400 ohms

Sorry mis read the OP didn't see the M after 400, reminder go to specsavers

 

[Pete999]

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 ?

No Marc I misread your post, thought you had said you had measured 400 ohms IR missed the dirty great capital M, sorry for any confusion

 

[UNG]

What make is the tub and the control equipment?

 

[marc8]

What make is the tub and the control equipment?

hi think it was Aqua spa but will check when I go back thanks, probably tomorrow if the rain stops

 

[marc8]

No Marc I misread your post, thought you had said you had measured 400 ohms IR missed the dirty great capital M, sorry for any confusion

no problem, I thought I had missed something really obvious