Advice for the Mobile and Seasonal RV Campers
Today’s site hydro demand has skyrocketed since the early days when hydro was first installed into campgrounds Now we have A/C Units, Microwaves, Toasters, Toaster Ovens, Coffee Makers, Sewing Machines, TV’s, VCR’s DVD Players, Electric Fireplaces, Dishwashers. Most of these were still in the dream stage when the hydro circuits were installed in some of these RV Campgrounds, and as such the grid was not designed to handle this type of load.
The rules have changed regarding the design of circuits required to feed these sites. CSA came up with a set of rules they called the Canadian Electrical Code in 1927 . The new 2015 version will be the 23 edition. These rules were in the guise of a suggestion and had no teeth. The Ontario Electrical Safety Authority(OESA) came into being in 1999 with a mandate from the Ontario Government. The OESA make the laws in Ontario regarding electrical matters and decreed that the rules as laid out in the Canadian Electrical Code would be the law of the land in Ontario and called them the Ontario Electrical Safety Code.
The Ontario Government also decreed that the Association of Professional Engineers of Ontario would have sole jurisdiction regarding Professional Engineering matters in Ontario, and only a member in good standing with the appropriate license could perform professional engineering duties. Along came the Association Of Certified Engineering Technician and Technologists(OACETT) and the rules changed again. Certified Engineering Technicians and Technologists were empowered to perform professional engineering duties under the auspices of a professional engineer.
The result of all this is that there is now a set of rules in place that outline what can or cannot be done with hydro electric circuits and who is allowed to design and implement these circuits.
Unfortunately these rules are often ignored for many possible reasons. In many cases the grid was in place long before the rules, however, any modifications or changes must conform to the rules.
Electrical Authority
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Ontario Electrical Safety Authority – The legal entity that governs electrical construction in Ontario
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Ontario Electrical Safety Code – The Law in Ontario
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Canadian Electrical Code – A set of Rules on paper created by the Canadian Standards Association\ (CSA) and adopted into law by the Ontario Safety Authority
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Hydro One
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Association of Professional Engineers of Ontario (APEO) – The Legal Authority that governs Engineering Work in Ontario.
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Association of Certified Engineering Technicians and Technologists (OACETT). Allowed to do engineering work under the auspices of a Professional Engineer.
ESA Electrical Safety Code
The Electrical Safety Authority is designated by Ontario Regulation 89/99 as the responsible authority for purposes of section 113 of the Electricity Act, 1998 and regulations made thereunder. The only such regulation is Ontario Regulation 164/99 as amended by Ontario Regulation 10/02. This regulation adopts, by reference, the Canadian Electrical Code together with specific Ontario amendments and is referred to as the Ontario Electrical Safety Code (the OESC).
The Ontario Electrical Safety Code is primarily a technical document and it is prescriptive in approach. The OESC describes the standards for electrical installations in detail.
Risk associated with technical compliance can be decreased by taking appropriate measures to ensure that those who perform electrical work are qualified, competent and appropriately certified or licensed.
The Code is developed through the efforts of a number of committees representing electrical expertise and knowledge from across Canada and the U.S. The Ontario Electrical Safety Code is law in Ontario, and as such defines the legal requirements for safe electrical installations and products/equipment in Ontario. To ensure that the Code reflects changes in technologies, and responds to reports of electrical incidents, the Code is updated every three years. Changes to the Code are documented on an ongoing basis.
Ref: http://www.esasafe.com/about-esa/governance-and-regs/electrical-safety-code
Canadian Electrical Code – Rule 8 – 102 Summary (see Attachment 5)
Rule 8-102 -1
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Maximum voltage drop in a feeder circuit is 3%
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Maximum voltage drop in a combined feeder and branch circuit is 5%
Rule 8-102 -2
The Load is unknown so the the voltage drop is calculated at
80% of the Circuit Breaker Rating = 24A for a 30A breaker at 120V.
This means that the voltage can only drop by 6V at the load device, using the 5% rule.
The CEC Table D3 for #10 Copper at 25Amps with 1% Voltage drop has maximum distance of 6.2 Meters. At 3% = 6.2*3=18.6 Meters and at 5% 6.2*5= 31 Meters. (101.7 ft)
(Ref:Attachment 6 – CEC Table D3)
To meet CEC Code requirements the Trailer Circuit breaker should be within 18.6 Meters (61 Feet) of the Circuit breaker in the Main Distribution Panel with #10 wire. 3% = 18.6M
Opinion of the Author
The CEC keeps using reference to 120V as the nominal. There is no reference to special treatment for RV Campgrounds or 125V Nominal Voltage. However campgrounds are using the upper taps on the transformers to raise the voltage closer to 125V, so that the voltage drop in the long cables will have less of an impact on the users equipment. The American National Electrical Code (NEC) recognises this and, for Campgrounds, uses the 125V nominal voltage.
We should be more concerned with the actual voltage at the site when under load than how much it drops. How much it drops is really immaterial as the grid line voltage varies between 125 to 106 volts.
A Voltage drop of 5% in the feeder and branch circuit is the maximum per CEC Rules. That’s 6V calculated at the nominal 120V. per Rule 8 102
1) 125V-6V=119V – This is Good
2) 120V-6V=114V – This is Good
3) 115V-6V=109V – This is NOT Good but OK
4) 110V-6V=104V – This is NOT OK
Lines 1 and 2 are code compliant. Line 3 is marginal but ok.
Line 4 is not code compliant and has dropped into the region where damage may occur to camper equipment.
The Following is taken from the NEC
(Shows the 125V Nominal Reference)
551.81 Receptacles
A receptacle to supply electric power to a recreational vehicle shall be one of the configurations shown in Figure 551.46(C) in the following ratings:
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50-ampere — 125/250-volt, 50-ampere, 3-pole, 4-wire grounding type for 120/240-volt systems
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30-ampere — 125-volt, 30-ampere, 2-pole, 3-wire grounding type for 120-volt systems
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20-ampere — 125-volt, 20-ampere, 2-pole, 3-wire grounding type
for 120-volt systems