ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Increasing demand factors in residential
by gfretwell - 03/28/24 12:43 AM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
Cordless Tools: The Obvious Question
by renosteinke - 03/14/24 08:05 PM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
1 members (Scott35), 262 guests, and 14 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#71088 10/21/06 12:46 PM
Joined: Feb 2005
Posts: 16
D
Member
Anyone have a suggestion on an affordable meter/recorder. I am trying to test for a circuit being turned off in the middle of the night. I have traced it and can not find the circuit switched. The circuit is for emergency lighting and I am having to replace batteries every month

#71089 10/21/06 02:25 PM
Joined: Nov 2005
Posts: 827
Likes: 1
J
Member
Why don't you start by just using an indicating cube relay and a NO push button. Wire the PB and contact in parallel between the line and relay coil and return the other end of the coil to neutral. Energize, push the button and leave. If you come back to find a dropped relay, you know you had an interruption.

You could get more info by leaving the push button out and using your contacts to drive a battery powered hour meter and/or cycle counter. A N.C. contact could drive the hour meter to log the cummulative time of power off while the other N.C. (or N.O.) contact could drive the counter. If you don't need time stamping, you're done.
Joe

#71090 10/21/06 02:35 PM
Joined: Mar 2005
Posts: 1,213
S
Member
Could you set up a camcorder to record some of the lights on the circuit? Would have a timecode tag, too.

#71091 10/21/06 04:59 PM
Joined: Apr 2002
Posts: 7,381
Likes: 7
Member
Denver:
Are you saying you can't find the emergency light circuit??

E-ltg should either be on the local ltg circuit, before switch, or a dedicated circuit with a breaker lock.

Methods outlined above are great ways to determine time of power off.

If you 'find/know' what circuit feeds the e-lites, just put a handle lock on it.

John


John
#71092 10/21/06 06:01 PM
Joined: Feb 2005
Posts: 16
D
Member
Joe- exalent idea thanks
Steve- Federal campus, Cams a BIG NO NO
HotLine1- Traced the circuit back to panel I have found no switches and i installed lock on breaker. This place (as most Fed locations) has outside contractors inspected very poorly or never.

#71093 10/21/06 07:45 PM
Joined: Mar 2005
Posts: 1,213
S
Member
Denver, just because it's federal doesn't automatically rule out cameras. I just sort of threw it out there as an idea, but if it's something you want to try, don't just disregard it- it's all a matter of asking the right person. Especially if the area you want to set the camera up at is unclassified! Ask your sponsor, they can talk to the security manager on your behalf. Heck, they might already have the info you need on the security cameras!

Really, if this is a secure area, you'd have to go through the same security procedures with anything capable of data logging. It would be harder to get permission to set it up in a secure area, but since you don't really need the tape, you could view it right there under the supervision of your escort and have the tape destroyed when you've gleaned what you need from it.

Oh, a possibly easier idea- do you have an ammeter with a min/max setting and an AC/DC adapter? You could clamp an emergency cable, set it on min, and see if it reads 0 the next morning. Or if the batteries in your ammeter are dead when you come in, that's probably a good indication, too!

Edit: idea2: splice a wall clock onto one of the emergency light circuits [Linked Image] Won't tell you when the outage happened, but will tell you exactly how long it was!

[This message has been edited by SteveFehr (edited 10-21-2006).]

#71094 10/21/06 08:18 PM
Joined: Jan 2005
Posts: 5,445
Likes: 2
Cat Servant
Member
I think that you're on the right track with a recording type of device. Indeed, since the problem may be intermitant -say, only on Saturday morning- you'ld want to record for a greater period than one night.

BUT- since we have no idea what's going on, why don't we start from scratch?
Verify the volts into the units. Then, verify the volts arriving at the batteries. It isn't impossible that the units themselves are killing the batteries.
Be alert of over-voltage as well as under-voltage. Heat is a real battery killer- and feeding a battery too many volys will kill it quickly.

Indeed, you might place a thermometer in the units. If these are tamper-resistant fixtures, they could very well be too hot. Especially if the night crew covers them up so as to sleep better! I think medical thermometers have a 'stop' that holds the high reading.

Some places have folks with way too much time on their hands. Some bored folks might be cycling the test buttons- either just for fun, or for some light after 'lights out.' Either case, repeated charge cycles probably aren't good for the batteries.

Absent a proper chart recorder, you're left to improvising. I'd wire a small clock, or electromagnet, inside one of the units. These will at least indicate (depending on how wired) if the test button was pressed or the power failed at some point.

I really can't think of an over-voltage indicator, though.

#71095 10/21/06 09:03 PM
Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
You should be able to rent a recording volt meter. If you were any closer I would lend you my Dranitz. That will give you a log of any event on the power lines


Greg Fretwell

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5