The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Calling all Non-US members!! (Non-US only)
by aussie240
Yesterday at 02:39 AM
Photo Upload Tutorial
by DanK
12/06/16 11:35 PM
Sprinklered equipment 26-008
by bigpapa
12/02/16 04:24 PM
On Delay Relay with Auto Reset
by Potseal
12/01/16 09:59 AM
Wow, that was close!
by jraef
11/28/16 07:06 PM
New in the Gallery:
12.5A through 0.75mm flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 13
HotLine1 9
Texas_Ranger 8
sparkyinak 7
Trumpy 6
Who's Online
0 registered (), 238 Guests and 5 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#102596 - 06/15/06 08:08 PM 26-218
jay8 Offline
Member

Registered: 07/28/05
Posts: 183
Loc: Vancouver, BC
I plan to replace power factor correction capacitors inside a wye-delta starter. Existing capacitors were damaged due to a wiring fault. 26-218 2(d) does not let me put capacitors on the load side of the starter if it is wye-delta starting, but I am replacing existing capacitors, installed by the manufacturer. What gives? Why cant I do this in the field, when it is an accepted industry practice? Any ideas out there? Thanks.

Top
2014 / 2011 NEC & Related Books and Study Guides
#102597 - 06/15/06 08:29 PM Re: 26-218
twh Offline
Member

Registered: 03/11/04
Posts: 898
Loc: Regina, Sask.
If I were replacing parts on CSA approved equipment, I would do it in a manner that would restore the equipment to the condition at which it was approved. I don't think that it is up to us to question the CSA approval.

As to it being an industry practice - perhaps it isn't a good practice.

Top
#102598 - 06/16/06 04:12 PM Re: 26-218
mikesh Offline
Member

Registered: 06/07/06
Posts: 614
Loc: Victoria, BC, Canada
Ok it has been 15 years since I last wired a Y / delta starter but from memory the y has windings that are shorted in y then open and reconnect delta. So there is a moment where there is no voltage on the wires that were shorted at the y point. Put a capacitor across the output and it would discharge during the transition possibly creating a problem. If I recall, the capacitors should not be connected until the motor reaches operating speed. There may also be tourque issues but on that point I think I am confusing the capacitor in single phase motors with power factor correction capacitors.
I might ask if a factory supplied y/delta with PF correction does not have a set of contacts that don't close until after the motor is Delta?

Top
#102599 - 06/17/06 09:04 PM Re: 26-218
jay8 Offline
Member

Registered: 07/28/05
Posts: 183
Loc: Vancouver, BC
The starter is wired in such a way that the capacitors come online when motor has completed its transition from wye to delta. 26-218 refers to overvoltages and overtorques, reclosings, jogging etc. But because the caps come online after transition, and there is no way these machines I am working with are going to be jogging frequently, I dont see the problem.

Top
#102600 - 06/19/06 04:10 PM Re: 26-218
mikesh Offline
Member

Registered: 06/07/06
Posts: 614
Loc: Victoria, BC, Canada
So Jay I gather your starter is an approved unit that does not connect the capacitors until the motor is to operating mode. So I see no violation here. Approved starter with PF correction included is not the same as making one yourself. Make one yourself and you would be in violation.

Top



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals