Hi All,
first time poster and hoping someone can give me some advice.
End of last year connected and energised an air source heat pump, run from a 18th edition consumer unit. Customer wasn't happy as the kit (supplied by him) just cycled from freezing up to defrosting itself with the hot water it had produced. No technical support from the manufacturer, so he bought a replacement unit from a different manufacturer. A couple of months later the new unit is fitted and connected using the existing wiring and on first commissioning it the RCD 'protecting' that side of the DB trips. A new HP is delivered and fitted and has exactly the same issue. Tried supplying the unit from a separate 2 way DB, bypassing cabling in house with a temp cable, only heat pump and control circuit connected - same problem. So today I tried a different brand of RCD, in the separate DB and the unit works fine!! replace the original RCD module into the house DB and the trip returns, temporarily fit different brand into main DB and the unit runs fine.
original RCD - 2 pole proteus type A
replacement RCD wylex type a
both 80a 30ma
both ramp test at 29ma
all trip times fine
new supply, pme
controls are on same side of board as pump supply and use a bus system so 'no' voltage
IR reading for supply cable to HP tested fine on all three tests (with hp not connected)
I originally thought perhaps a proteus rcd problem, have now tried 3 different proteus modds all with the same result
but it dawned on me earlier that the proteus one could be fine and the wylex is faulty!!
completely baffled! Can't come up with a situation where one make is fine and another isn't when they appear to be working at the same trip level.
anyone any ideas? tia
first time poster and hoping someone can give me some advice.
End of last year connected and energised an air source heat pump, run from a 18th edition consumer unit. Customer wasn't happy as the kit (supplied by him) just cycled from freezing up to defrosting itself with the hot water it had produced. No technical support from the manufacturer, so he bought a replacement unit from a different manufacturer. A couple of months later the new unit is fitted and connected using the existing wiring and on first commissioning it the RCD 'protecting' that side of the DB trips. A new HP is delivered and fitted and has exactly the same issue. Tried supplying the unit from a separate 2 way DB, bypassing cabling in house with a temp cable, only heat pump and control circuit connected - same problem. So today I tried a different brand of RCD, in the separate DB and the unit works fine!! replace the original RCD module into the house DB and the trip returns, temporarily fit different brand into main DB and the unit runs fine.
original RCD - 2 pole proteus type A
replacement RCD wylex type a
both 80a 30ma
both ramp test at 29ma
all trip times fine
new supply, pme
controls are on same side of board as pump supply and use a bus system so 'no' voltage
IR reading for supply cable to HP tested fine on all three tests (with hp not connected)
I originally thought perhaps a proteus rcd problem, have now tried 3 different proteus modds all with the same result
but it dawned on me earlier that the proteus one could be fine and the wylex is faulty!!
completely baffled! Can't come up with a situation where one make is fine and another isn't when they appear to be working at the same trip level.
anyone any ideas? tia