Discuss testing a B&B without disconnecting bonding in the Periodic Inspection Reporting & Certification area at ElectriciansForums.net

Status
Not open for further replies.
S

shedhopper

Hi This is my first post. I'm trying to test a working hotel / B&B at the moment and even though I'm Insulation resistance testing live AND neutral to earth on the lighting circuit as an agreed limitation; I'm still getting a zero reading. I suspect it might be something to do with 16th Ed bonding but I can't disconnect the bonding conductors at the board as there are people in the property at all times. Has anyone had an experience like this? Any suggestions how I could proceed or should I just tell the owner that a working hotel is an un-testable hotel?
Thanks a lot
 

somersetsparks

Regular EF Member
Messages
1,251
If its a 3 phase DB with a triple pole switch, then unless you switch off and disconnect the neutral link you will always have N-E continuity (PME). If its single pahse with main switch off then it sounds like you have a fault?
 

Adam

Regular EF Member
Messages
186
Location
South Birmingham
I presume this is with the neutral disconnected from the Neutral bar?

If so, it will most likely be due to a borrowed neutral, that will still be connected to neutral bar.

Are most of the insulation resistance readings high?
 
OP
S

shedhopper

Hi yes it's single phase with the main switch off. You're right it could always be a fault, I just thought I'd post in case anything obvious I'd missed came up. Thanks a lot
 
OP
S

shedhopper

Yes neutral disconnected, most other IR readings are nice and high. There are still a couple of untested circuits in the DB so I'll look out for that. Thanks
 

somersetsparks

Regular EF Member
Messages
1,251
Hi yes it's single phase with the main switch off. You're right it could always be a fault, I just thought I'd post in case anything obvious I'd missed came up. Thanks a lot
Fault it is then! as has been suggested the borrowed neutral could be a likely candidate for a 0.00 or very low reading, try it on the low ohm's scale. Good luck!
 
OP
S

shedhopper

Good to know its not the bonding then, thanks. Yes the neutral is disconnected, I'm testing the circuit on its own, not the entire DB at once. Whe I go from Low Ohms to Meg Ohms the reading is clear, waiting for me to hit test (meger 1720)
 

Adam

Regular EF Member
Messages
186
Location
South Birmingham
Will you be disconnecting every circuit in the DB to test?

If so, you may find another circuit with very low reading. If this happens, disconnect both circuits neutrals (with circuits isolated, of course) and try the test again. If the test is clear with both removed, it is most certainly a borrowed neutral.
 
Status
Not open for further replies.

Electrician Talk

Top