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

ECN Shout Chat
Top Posters(30 Days)
Admin 16
Recent Posts
ESA Arc flash course
by TheShockDoctors. 03/24/17 10:15 AM
fuse rejectors
by HotLine1. 03/24/17 07:53 AM
Another Forum Update
by Admin. 03/22/17 03:04 PM
Dining room plugs
by watersparkfalls. 03/21/17 10:31 PM
by jraef. 03/21/17 09:13 PM
New in the Gallery:
SE cable question
Popular Topics(Views)
231,340 Are you busy
166,077 Re: Forum
160,541 Need opinion
Who's Online Now
0 registered members (), 82 guests, and 12 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#102596 - 06/15/06 11:08 PM 26-218  
jay8  Offline
Joined: Jul 2005
Posts: 183
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.

Tools for Electricians:

#102597 - 06/15/06 11:29 PM Re: 26-218  
twh  Offline
Joined: Mar 2004
Posts: 903
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.

#102598 - 06/16/06 07:12 PM Re: 26-218  
mikesh  Offline
Joined: Jun 2006
Posts: 613
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?

#102599 - 06/18/06 12:04 AM Re: 26-218  
jay8  Offline
Joined: Jul 2005
Posts: 183
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.

#102600 - 06/19/06 07:10 PM Re: 26-218  
mikesh  Offline
Joined: Jun 2006
Posts: 613
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.

Member Spotlight
Blue Collar Country
Posts: 5,316
Joined: January 2005
Show All Member Profiles 

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.019s Queries: 14 (0.003s) Memory: 0.7659 MB (Peak: 0.9043 MB) Zlib enabled. Server Time: 2017-03-24 20:02:43 UTC