ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Trumpy 5
Recent Posts
What do you do?
by ghost307. 09/22/17 08:26 AM
Another generator question
by gfretwell. 09/21/17 02:41 PM
Supporting conduit bodies
by ghost307. 09/18/17 12:12 PM
Thermal Imaging Camera upgrade
by Potseal. 09/18/17 11:57 AM
Linear Power Supply Quits Under Load
by JoeTestingEngr. 09/15/17 11:37 PM
New in the Gallery:
Gallery Test
Popular Topics(Views)
240,874 Are you busy
176,625 Re: Forum
168,537 Need opinion
Who's Online Now
0 registered members (), 62 guests, and 7 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#179233 - 07/02/08 12:26 PM 2 phase services  
junkcollector  Offline
Member
Joined: Apr 2007
Posts: 36
Central MN
This topic has probably been brought up here before, but through some searching I found nothing. (Sorry if I'm beating a dead horse sleep )

My question is, has anyone worked in a building that had 2 phase power? Was it POCO supplied, if so, could you explain the transformer hookup? (If overhead) What kind of disconnects / panelboards where used? I seen a few pictures of a smaller 2 phase service on a home inspector site. I consisted of 2 FPE panelboards, both feed with 2 hots and shared a nuetral. The meter said 2 phase, 5 wire. It had 5 wires for a utility drop. (Pics didn't show transformer hookup)

Just wondering if anyone had any information or examples on what a service consisted of. I know this is pretty much an obsolete system, but may well still exist in larger cities so it would be interesting to know how modern components, panelboards, etc are connected. I have seen diagrams and schematics for a Scott-T connection, and the theoretical aspects of changing 3 phase to 2 phase make sense, I was more or less wondering about the physical aspects.

Thanks everyone for any tidbits you can provide. smile


Work Gear for Electricians and the Trades

#179242 - 07/02/08 09:30 PM Re: 2 phase services [Re: junkcollector]  
JBD  Offline
Member
Joined: Jul 2001
Posts: 599
WI, USA
I have seen diagrams in literature from Cooper Power Systems and in Ugly's book.

The common conductor needs to be sized very carefully. On a standard 2-phase 3-wire circuit the common conductor needs to be 1.414x the line conductors.


#179255 - 07/03/08 03:18 PM Re: 2 phase services [Re: JBD]  
RODALCO  Offline
Member
Joined: Dec 2005
Posts: 854
Titirangi, Akld, New Zealand
The meter 2 phase 5 wire has the following terminals.

Phase 1 line
Phase 1 load
Phase 2 line
Phase 2 load
Neutral

so 5 wires are used.


The product of rotation, excitation and flux produces electricty.

#179305 - 07/05/08 09:27 PM Re: 2 phase services [Re: RODALCO]  
JBD  Offline
Member
Joined: Jul 2001
Posts: 599
WI, USA
Originally Posted by RODALCO
The meter 2 phase 5 wire has the following terminals.

Phase 1 line
Phase 1 load
Phase 2 line
Phase 2 load
Neutral

so 5 wires are used.


A 2-phase 5-wire system is basically (2) 3-wire systems, loads were never connected between Phase 1 and Phase 2.



Member Spotlight
HCE727
HCE727
Delaware County, PA, USA
Posts: 186
Joined: November 2005
Show All Member Profiles 
Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.016s Queries: 15 (0.003s) Memory: 0.7603 MB (Peak: 0.8927 MB) Zlib enabled. Server Time: 2017-09-22 22:20:47 UTC