Electric garage door trips rcbo

[gaz05]

Hi, I'm having trouble with a garage door, was on a single socket on a re-wireable board working fine. Changed the board to an rcbo tried it on a type c 20a and was ok until you tried to open the door and the breaker tripped also tried on a type c 16a rcbo to see if there was a fault with the rcbo and it did the same, this is on it's own circuit. Have opened the door by hand to see if it was catching but seemed to operate freely so don't think the motor is jamming/put under extra stain to open or close.
The door is a couple of months old and there is no paper work with it other than a brochure that says the company uses 'Somfy motor units' from a quick search on google I've found this,

SOMFY United Kingdom - AC Motors

If it is either of those doors the max current usage could be 3.15A, not sure what it draws to start but I'm scratching my head on why the breaker is tripping? It's been a long day and guessing I'm missing something fairly obvious.. I popped the cover off the control unit in the garage and there were two adjustable knobs with fuse embossed on them, no idea what fuses they are for. As you can tell I've never dealt with electric garage doors before so any help would be much appreciate!! Thank you

 

[Deleted member 9648]

It's an RCD as well as overcurrent.... test for low IR readings which may operate the RCD side of the RCBO.

 

[gaz05]

Thanks Wirepuller, sorry I should have put in the original post, the board is in the garage, the socket to power the door looks like it was a recent add on to the old fuse board for the door, the cable is maybe 3 ft in length and looks pretty much brand new IR reading are greater than 1999M ohms on l-n, l-e and n-e. You can plug the motor into the socket and the rcbo doesn't trip until you try to open or close the door.

 

[timo1]

If its tripping the moment a load is added could it be a damaged cable? had something similar happen to me and it was a metal screw of a backbox touching the earth terminal when the socket was tightened....does it hold when you test for nuisance tripping on rcd test?

 

[yellowvanman]

Need to check if its an overcurrent trip or an earth leak trip.

Try a standard MCB first and if that trips its obviously overcurrent, if not then there is a problem with the door!

 

[gaz05]

Will do a ramp test tomorrow and see what it holds at didn't think to do one earlier... and yellowvanman will grab a standard mcb in the morning and try that too! Thanks

 

[malcolmsanford]

When you say you changed the rewirable board, was this a full CU change, as this sounds remarkably like you may have put the neutral in the wrong bar.

 

[RogertheBodger]

By fitting an RCBO you may have uncovered an existing earth fault on the motor itself, only shows itself when the motor is energized, this fault wouldn't have shown up on a rewirable, Pat testing the motor would tell you.

 

[telectrix]

could it be N/E reversal in the plug/socket for the door?

 

[gaz05]

malcomsanford got it, but it was incorrect polarity on the outgoing side of the control unit. Took the cover off it this morning and n and pe were in the opposite terminals. Thank you to everyone that replied!! Much appreciated.