ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
220/230/240V 60Hz Systems
by gfretwell. 09/23/18 02:50 PM
Inspection camera help
by petey_c. 09/22/18 07:52 AM
Motion detectors and dimmers
by gfretwell. 09/20/18 04:02 PM
Extension cords
by annemarie1. 09/20/18 08:54 AM
Acronis Backup 2017
by gfretwell. 09/16/18 12:46 AM
New in the Gallery:
Plug terminals
Housebilding DIY wiring
Who's Online Now
0 registered members (), 8 guests, and 28 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
2 phase services #179233
07/02/08 12:26 PM
07/02/08 12:26 PM
J
junkcollector  Offline OP
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
Re: 2 phase services [Re: junkcollector] #179242
07/02/08 09:30 PM
07/02/08 09:30 PM
J
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.

Re: 2 phase services [Re: JBD] #179255
07/03/08 03:18 PM
07/03/08 03:18 PM
R
RODALCO  Offline
Member
Joined: Dec 2005
Posts: 856
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.
Re: 2 phase services [Re: RODALCO] #179305
07/05/08 09:27 PM
07/05/08 09:27 PM
J
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.


Featured:

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

 

Member Spotlight
RH1
RH1
California
Posts: 22
Joined: August 2009
Show All Member Profiles 
Top Posters(30 Days)
Admin 13
Trumpy 11
Popular Topics(Views)
249,419 Are you busy
187,341 Re: Forum
176,681 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.020s Queries: 15 (0.003s) Memory: 0.9603 MB (Peak: 1.0914 MB) Zlib enabled. Server Time: 2018-09-24 05:43:10 UTC