ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
Lock-down Thread
by NORCAL - 02/26/21 07:28 AM
Northern Tool Recalls Powerhorse Generators
by Admin - 02/25/21 09:49 PM
You will never guess
by gfretwell - 02/25/21 07:48 PM
New tool
by SMOKEYBOB - 02/15/21 04:59 PM
New in the Gallery:
Facebook follies, bad wiring
FPE in Germany pt.2
Who's Online Now
1 registered members (Scott35), 15 guests, and 18 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
using stinger to nuetral from 3ph delta #179256 07/03/08 02:47 PM
Joined: Sep 2006
Posts: 155
C
crselectric Offline OP
Member
I've got a 208v 2wire kiln to hookup, can I use the stinger to neutral from a 240v delta 3ph? for a 59amp 2wire plus ground hookup. I read 208v to ground from the stinger. si there a code issue? and for ocpd can I use 1 leg of a 2pole breakr or should I find a 1pole 70 amp? thanks again chris

Work Gear for Electricians and the Trades
Re: using stinger to nuetral from 3ph delta [Re: crselectric] #179259 07/03/08 03:26 PM
Joined: Jan 2005
Posts: 5,316
renosteinke Offline
Cat Servant
Member
I've always been told not to do it, but I can't see a theoretical reason.

There IS a code reason ... namely, that the single pole breaker is almost certainly not listed for more than 150 v. line to neutral. Indeed, even the two pole breakers in that panel ought to be specifically listed for the use .... though I admit that they usually are not! Most two pole breakers are not listed for use with a 'stinger' either.

Another code reason is found on the panel itself. Reading the fine print on the label, again, the panel is listed only for two pole or three pole circuits with a delta service. What you're supposed to do is use this panel to feed a separate single phase panel.

Re: using stinger to nuetral from 3ph delta [Re: renosteinke] #179266 07/03/08 08:20 PM
Joined: Jul 2004
Posts: 9,569
G
gfretwell Offline
Member
The hardware question would be, is this real 3 transformer delta? If it is Delta Vee with 2 transformers you will drag one side down (BC vs BA) and the other one up.


Greg Fretwell
Re: using stinger to nuetral from 3ph delta [Re: gfretwell] #179270 07/03/08 09:14 PM
Joined: Sep 2006
Posts: 155
C
crselectric Offline OP
Member
it must be a delta vee, there are two transformers on the pole one large and one small, pge hooked them up when we put the service in, I was only a apprentice at the time, and havent looked at the hookup to the four sets of parallel 250s we pulled in. I'll have to look up delta vee set ups, but will just tell the client to get new elements. chris

Re: using stinger to nuetral from 3ph delta [Re: crselectric] #179271 07/03/08 09:57 PM
Joined: Jul 2004
Posts: 9,569
G
gfretwell Offline
Member
You also have to be careful with 240 single phase loads on that setup. Be sure it is using the 120/240 transformer not the stinger leg ... for the same reason. We used to run into that problem in computer rooms that were on delta services. If you can keep your single phase loads balanced around the phases you can get away with it but if they are lopsided AB/BC it can screw up the balance. (assuming orange is B)


Greg Fretwell
Re: using stinger to nuetral from 3ph delta [Re: gfretwell] #179306 07/05/08 08:38 PM
Joined: Jul 2001
Posts: 599
J
JBD Offline
Member
Any load connected to the stinger to neutral reduces the ability of the transformer to handle other "normal" line to neutral loads.

Theoretically it is possible, practically it is not advised.

Re: using stinger to nuetral from 3ph delta [Re: JBD] #179308 07/06/08 10:56 AM
Joined: Sep 2006
Posts: 155
C
crselectric Offline OP
Member
the kiln says its 59 amps at 208, I called the mfg. tech, he said it would increase the amps on the circuit if run at 240v, but I think he was wrong wouldnt it lower them at 240v, this is SKUTT kilns and they build for both 208 and 240 and have electronic time/temp controllers, are there different electronics for 208 and 240? or wouldnt it be just rated for 250v, and its a resistive load so wouldnt it just get up to temperature faster? Sorry if this might seem basic, but my daddy brain isnt what it once was and its not always possible to get a quiet space. thanks again, chris

Re: using stinger to nuetral from 3ph delta [Re: crselectric] #179309 07/06/08 01:00 PM
Joined: Jan 2005
Posts: 5,316
renosteinke Offline
Cat Servant
Member
When you change the voltage, a heating element is affected by the square of the change. That is, double the volts, get four times the heat.

The kiln maker ought to have replacement parts that are rated for 240 volts. This is the best solution; I've had to make such changes on commercial water heaters.


Featured:

2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
SafetyWired
SafetyWired
Pa, USA
Posts: 44
Joined: July 2013
Show All Member Profiles 
Top Posters(30 Days)
Popular Topics(Views)
275,411 Are you busy
209,304 Re: Forum
196,593 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3