Regulatory question regarding maximum cable length - Page 1
Forum section: electronics / beginners

author: indole
author_rank: Unknown
timestamp: July 29, 2014, 04:35:00 pm
content: This isn't quite an electronics question but more a electrical regulatory question (in particular for Ontario, Canada if that matters).In my work lab I have a natural gas tobacco dryer (De Cloet if anyone knows) and the current electrical cord is too short to reach the outlet, so when I need to use it I've been using an extension cord to Health/Safety officers dismay. To alleviate the problem I can either have a new outlet wired ($$$) in so the existing cord will reach or my solution was to find a suitable rated cord and replace the old one with it. The current cable is Coral S00W 12/3 rated for 600V and is about 1m in length. To be able to reach the existing outlet an additional 1m would be required.I proposed that to facilities to have that done but they rejected it saying that code dictates the maximum length and if we change it we would be violating code.I went through the CSA electrical code and cannot find anything stating a maximum length of cable so I'm having trouble understanding why this is not possible.If this is not possible due to the regulations, what section of the code does it fall under so I can educate myself on the matter.Thanks!

author: Zero999
author_rank: Super Contributor
timestamp: July 29, 2014, 10:09:03 pm
content: I don't know about the regulations in your area.Generally the maximum cable length depends on the acceptable volt drop and the short circuit current being high enough to trip the breaker in time to adequately protect against fire and electrical shock.There is no limit on cable length as long as the cable cross-sectional area (conductor thickens) is sufficient to ensure a low enough voltage drop and sufficient short current to trip the breaker.

author: tautech
author_rank: Super Contributor
timestamp: July 29, 2014, 10:17:06 pm
content: Use this cable calculator:http://www.generalcable.co.nz/Home/Customer-Services/GenCalc.aspx

author: Kappes Buur
author_rank: Regular Contributor
timestamp: July 29, 2014, 10:54:46 pm
content: While the CSA code is universal throughout Canada, there are also additional rules and regulations for each province and municipality.Of course, an additional walloutlet would be the preferred method.If you have to use an extension cord, use a single extension cord of the proper rating instead of two extension cords in series.See also:http://www.uottawa.ca/services/ehss/docs/electrical_safety_guide_2004.pdfhttp://carleton.ca/ehs/wp-content/uploads/Safety-Sheet-1-Electrical-Safety-Guidelines_FINAL.pdf

author: AlfBaz
author_rank: Super Contributor
timestamp: July 29, 2014, 10:55:50 pm
content: Most of the electrical wiring standards here in Australia closely follow or reflect IEC standards. To that end the rules here stipulate that no more than a 5% voltage drop shall exist from the source to the load. I highly doubt adding 1 meter will effect the voltage drop anywhere near that. The only other thing I can think of is there may be rules governing appliances in your country that dictate maximum lead length on them.You best bet is to contact a local electrician or electrical service and ask them. Either way I wouldn't argue with safety people you're only going to loose, even if you are right

author: Unknown
author_rank: Unknown
timestamp: July 29, 2014, 11:02:46 pm
content: Quote from: indole on July 29, 2014, 04:35:00 pmDid they say it would violate your local electrical code specifically?They may have been referring to national/state/local/industry OH&S codes. I know of a few instances where non-detachable power cords >1.5m are against "code".

author: Richard Crowley
author_rank: Super Contributor
timestamp: July 29, 2014, 11:10:37 pm
content: I would ask them to cite chapter and verse. Many people have fuzzy notions of what "the code" says without any hard evidence.Is this a hobby activity, or is this part of some profit-making enterprise?When you say "Health/Safety officers" do you mean the inspectors from the applicable governmental authority?Or do you mean people in the employ of the enterprise?

author: indole
author_rank: Unknown
timestamp: July 30, 2014, 12:46:18 am
content: After more discussion with the electrical people, they clarified that it wasn't the length of the cable that is the problem but more or less it was never suppose to have a cable that is not hard-wired in. Apparently the equipment was originally intended to be hard-wired but when it was brought to the lab, it had a switch added and a cable so it could be plugged in, which is apparently not against code but isn't the best way to do it. The new proposed solution is to replace the the cable with BX cable and hard-wire it to the panel, which I'm more satisfied with.Thanks for the replies!

author: David Hess
author_rank: Super Contributor
timestamp: August 01, 2014, 08:31:35 pm
content: I have run across installations that had the opposite problem. Local codes required permanent installations to have extra expensive permits issued so the solution was to replace the fixed power cord with a removable one, install an outlet, and put the equipment on wheels so it could be pushed around. Of course this was shown to be a bad idea when the next earthquake occurred and the broadcasting equipment rolled away from the wall disconnecting the power at the remote site and shutting off emergency communications but it was completely legal.