starbreaker mcbs

[BES]

Job yesterday finding fault on RFC. All good found problem, sorted, turned main switch back on packing up tools tennent says no power to upstairs lights and to combi boiler. Checked board nothing off. Quick check at pendant in bedroom no power same at fcu for boiler(on own circuit). All other circuits working ok. Checked out going side of both mcbs feed circuits with no power again nothing. Turned everything off and removed mcbs from board checked for continuity from in and out side of mcbs both ok put back in board both circuits working fine ?. Tennent says that last time the power was turned of same thing happened but different ciruits ?. Its a crabtree starbreaker cu, the one with plug in busbar. Turned of power 2/3 times before leaving samething happened again lighting again and kitchen RFC obviously no right but why when you take breaker out then replace it corrects it self. Left all working ok.
Any ideas.

 

[D80]

Are the MCB's making a secure connection to the busbar? Never worked with Crabtree starbreaker, but on the Square D boards with the prongs it was occaisionally an issue that the breaker wouldn't make a good contact with the busbar.

 

[BES]

D80
Yeh seem to be.Like you not really had much to do with this type CU before. Just wondered if it was a common fault with this type.

 

[Guitarist]

If there is power on one side of the MCB but not the other till you operate it a few times or remove it from the source then it has to be the MCB (assuming you are testing both sides to earth or neutral). Maybe a bad batch as I haven't had any problems with them.

 

[Richard Burns]

I find it inconvenient to put starbreaker MCBs back in and so it may well not be making good contact with the busbar. Worth looking at the bus bar connection and see if there is damage to the busbar. Also once the MCB is in place then check the voltage on the incoming contact of the MCB to make sure there is good contact.

 

[Knobhead]

If they are the contacts I’m thinking of, square shaped but with an inverted “V” looking end on. They were prone to the push on contact going to far on to the bus bar tongue. This could give a break in continuity between MCB and bus bar. Basically they were carp.

 

[i=p/u]

probably why there loads of them prong breakers laqyin in front of van

 

[Knobhead]

Time for a clean out then. Once fitted and then removed they never go back right.

 

[i=p/u]

there not mine, .. i cant speak for other head the gratings

 

[BES]

Cheers for replies guys at least i know what im looking for next time . Ta.

 

[Engineer54]

I don't have any time for plug-in OPD's of any type or manufacturer, they are nothing but a source of trouble and inconvenience!! Another bad Yank idea, and if you have seen the amount of burnt and charred plug-in bus-bars on Yank boards as i have, you would never use them either!! lol!!!