S
Strawbs
Circuit: -
17th edition board with 30mA RCD
Pond pump circuit is a 16A MCB feeding double pole FCU with 3A fuse, this feed an electronic immersion heater timer, this is connected to a pond pump/filter unit via SWA.
Problem: -
RCD trips every time the pump switches OFF
What is connected to RCD: -
Socket ring for garage
House alarm system
Garage Door
Pond pump
What has been done so far: -
Initially the circuit was good and has worked well for several months, but recently the RCD started to trip when the pond pump switched OFF
Initially there were two pumps and a UV filter box, being controlled by a mechanical immersion heater timer, but one of the pumps started to fail so I obtained a new pump with an integral UV filter, so this combined pump has replaced the two pumps and the UV filter box. But the RCD kept tripping, so I replaced the mechanical timer with an electronic one, RCD still tripping.
Carried out insulation resistance on cables from CU to FCU and SWA cable, all OK (FCU, Timer and pump disconnected for test)
All cable connecting checked for security of attachment
Carried out RCD test, the RCD trips within 20ms @ 5I and trips at 27mA
All the cabling is less than 12 months.
L & N cabling within garage is 2.5mm singles in trunking with 1.5mm for the earth cable.
I do not have an earth leakage tester
Any ideas?
17th edition board with 30mA RCD
Pond pump circuit is a 16A MCB feeding double pole FCU with 3A fuse, this feed an electronic immersion heater timer, this is connected to a pond pump/filter unit via SWA.
Problem: -
RCD trips every time the pump switches OFF
What is connected to RCD: -
Socket ring for garage
House alarm system
Garage Door
Pond pump
What has been done so far: -
Initially the circuit was good and has worked well for several months, but recently the RCD started to trip when the pond pump switched OFF
Initially there were two pumps and a UV filter box, being controlled by a mechanical immersion heater timer, but one of the pumps started to fail so I obtained a new pump with an integral UV filter, so this combined pump has replaced the two pumps and the UV filter box. But the RCD kept tripping, so I replaced the mechanical timer with an electronic one, RCD still tripping.
Carried out insulation resistance on cables from CU to FCU and SWA cable, all OK (FCU, Timer and pump disconnected for test)
All cable connecting checked for security of attachment
Carried out RCD test, the RCD trips within 20ms @ 5I and trips at 27mA
All the cabling is less than 12 months.
L & N cabling within garage is 2.5mm singles in trunking with 1.5mm for the earth cable.
I do not have an earth leakage tester
Any ideas?