ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
MRI LED lights dimmer control replacement - wow!
by ghost307. 01/19/18 11:37 AM
Video: Inventor of the GFCI self-testing shocks
by Bill Addiss. 01/17/18 11:11 PM
FPE in Germany
by HotLine1. 01/17/18 07:07 PM
VDE 0100 to introduce AFCIs
by LongRunner. 01/17/18 10:32 AM
Fujifilm Recalls Power Adapter Wall Plugs
by Admin. 01/16/18 07:04 PM
New in the Gallery:
Housebilding DIY wiring
SE cable question
Who's Online Now
0 registered members (), 16 guests, and 14 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
outlet surge protection #13481
09/05/02 10:45 AM
09/05/02 10:45 AM
D
donles  Offline OP
Member
Joined: Apr 2001
Posts: 83
Pennsylvania
If anyone has read my recent posts, you know that I have been replacing ungrounded receptacles in a residence with grounding type. Also, so far this particular residence has no ground available in the device boxes. I'm running a seperate ground wire.
This has me wondering if those surge protection devices that plug into a grounding receptacle REQUIRE a ground to work properly. I noticed that the homeowner has a computer plugged into one of these and the receptacle has an open ground. Someone had improperly replaced an ungrounded receptacle with a grounding type. I have only grounded a few of their receptacles so far but I would like to advocate bringing some of these illegal ones up to code. In addition to making them code-compliant, I'd like to have a technical argument concerning the operation of the surge protection devices i.e. do they need a ground?
Don

Work Gear for Electricians and the Trades
Re: outlet surge protection #13482
09/05/02 10:56 AM
09/05/02 10:56 AM
T
tsolanto  Offline
Member
Joined: Sep 2002
Posts: 131
Long Island NY
Why don't you use GFI outlets to protect the circuit and then use 3 wire outlets on the load side of the GFI

Re: outlet surge protection #13483
09/05/02 01:25 PM
09/05/02 01:25 PM
Tom  Offline
Member
Joined: Jan 2001
Posts: 1,044
Shinnston, WV USA
IF you're looking at a good surge arrestor, it provides protection from line to neutral, line to ground and neutral to ground. Without an equipment ground, you've given up 2/3 of the protection.

There is no substitute for a proper equipment ground, especially when dealing with electronics. tsolanto's advice is fine in most cases, but you wouldn't see me betting my computer or TV on a circuit that does not contain an equipment ground.

Tom


Few things are harder to put up with than the annoyance of a good example.
Re: outlet surge protection #13484
09/07/02 01:18 AM
09/07/02 01:18 AM
C
Currently  Offline
Member
Joined: Apr 2002
Posts: 53
TN
Some surge protectors I have taken apart have MOV's in them. There is almost no protection if there is no ground. The MOV's "wear out" if they are constantly hit with spikes and such. Try telling someone to replace these every year or so and they look at you funny.

UPS manufacturers state that the circuit must have a ground for them to work.

I had a client that used to fry his computer equipment 3 times a year till I told him to hire an electrician to rewire his outlet. (had a ground outlet in an ungrounded 2 wire cloth romex circuit)
Static electricity is murderous to computer equipment in an ungrounded circuit.

Re: outlet surge protection #13485
09/07/02 10:12 AM
09/07/02 10:12 AM
P
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Yep, without a ground you'll lose all common-mode surge protection and only get differential protection, i.e. high voltages between hot & neutral.

If you connect up a lot of equipment with filters on the AC line there will also be appreciable capacitance from hot & neutral to your "floating ground." The casings will likely sit at about 60V to true ground.


Featured:

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

 

Member Spotlight
Posts: 165
Joined: March 2007
Show All Member Profiles 
Top Posters(30 Days)
Admin 20
sparky 15
Potseal 14
Popular Topics(Views)
243,554 Are you busy
180,360 Re: Forum
170,838 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.022s Queries: 14 (0.004s) Memory: 0.9671 MB (Peak: 1.1051 MB) Zlib enabled. Server Time: 2018-01-19 23:04:03 UTC