[Canada Code] Sharing 240V And 120V Appliance On Same Circuit In Workshop Shed? - Electrical - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Like Tree4Likes
Reply
 
Thread Tools
Display Modes
Old 10-12-2016, 01:44 PM   #1
Newbie
 
Join Date: Oct 2016
Posts: 18
Rewards Points: 36
Default

[Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


Hello,

I will be likely calling an electrician about this, but I need to check code for my area first...

My backyard has a brick shed (former garage) with a secondary fuse panel that I am looking to upgrade it to a secondary circuit breaker panel. But I've got a new catch-22 to solve, regarding sharing 240V and 120V appliances.

The main house currently has a standard 48-breaker 200A electric panel, with some breakers paired for 240V.

This is the current configuration:

(A) Paired breaker on main panel (240V 30A) ───> (B) 100ft run to shed ───> (C) Secondary panel (240V 30A) ───> (D) Two 120V fuses (120V 15A)


So each 120 volt 15A circuit is protected by the full chain:
Master house main breaker (200A) -> paired breaker (240V 30A) -> underground wire run -> secondary shed panel (240V 30A) -> two secondary fuses (120V 15A).

I have determined the wires are 10-gauge between the main house and the shed, approximately 50 to 100 feet underground shielded run in the dirt deep underneath patio stones, so I don't want to dig up the wire. But both ends are Red, Black, White, and there's a ground connection in the shed, so I have full 4-wire cability, just like a modern stove/dryer.

I have a need to install an Energy Star 240 volt variable-speed pool pump, but I don't want to lose the existing 120V GFCI outlets in the shed. There are 120V pumps too, but choices are limited. Max power would be 1 to 1.5 horsepower, so depending on pool pump efficiency, about 4 to 8 amp. This leaves about 22 amps of margin on a 30 amp circuit.

It appears if wired correctly, there can safely still have plenty of power left for the lightly used power outlets. This appears to be okay in code in some parts of the world, but I'm not sure about my area (Hamilton, Ontario, Canada).

This would be the desired new configuration:

The 240V pool pump would have this electrical path:
Main panel breaker (240V 30A) -> secondary panel (shed) master breaker (240V 30A) -> New pool pump

The 120V shed circuits would have this electrical path:
Main panel breaker (240V 30A) -> secondary panel (shed) master breaker (240V 30A) -> Secondary (shed) 120V breakers (120V 15A) -> shed GFCI outlets.

All of the wires (including neutral) between main panel and the shed are sized for 30 amps, and average pool pump amperage is relatively low (usually less than 3 amp in normal variable speed operation) and only one 15 amp (rarely) tool would ever be in use at a time, usually sub-7-amp 120V tools like drill chargers, bandsaw, etc. A small 400 watt electric heater is used (for frozen-pipe prevention).

It would surmise, that circuits would be protected by all of these, so if combined current ever exceeds 30A unexpectedly, things will safely trip anyway. And if a 120V appliance exceeds 15A, one of the two secondary panel breakers will likely trip before any 240V 30A breaker (either the house paired breaker or the secondary master breaker), but this configuration protects all scenarios of voltages and amperage, irregardless of which breaker trips.

Keep in mind given the master/secondary shed, this means 4 breaker layers between main supply and the 120V shed circuits (240V 200A master breaker -> 240V 30A paired breaker -> buried 10gauge run to shed -> 240V 30A secondary master breaker -> two 120V 15A secondary breakers -> GFCI outlets) ... The pool pump would have 3 breaker layers (being hooked after the secondary master breaker, but before the secondary 120V breakers). As described above, everything in the shed (240V and 120V) would be protected by 240V 30A breakers on both ends of the wire run between the house and the shed, protecting the wire from overcurrent scenarios. Hopefully this brings such a setup into code -- but I need to check.

However, while apparently legal in certain jurisdictions in the world, I am searching (with some difficulty) about legality of this for my area (Hamilton, Ontario, Canada).

It is too difficult/expensive to run new wire between the two buildings, because the brick shed at the rear of the backyard, behind a pool surrounded by patio stones -- it would be a nightmare dig-up scenario far, far more costly than electrical panel replacement. In fact, I've wired a secondary panel before and it would be an easy job for me -- my concern is residential code compliance and being legal for insurance purposes -- so an electrician will be involved to a certain extent.

I'll still be involving an electrician one way or another (I already do 120V circuits myself, but not 240V) -- but I'd like to figure out the answer first, as I'm having difficulty tracking this down.

Is code compliance achievable with the above setup in Ontario, Canada?
Comments?

Last edited by mdrejhon; 10-12-2016 at 02:10 PM.
mdrejhon is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 10-12-2016, 02:15 PM   #2
Super Moderator
 
joed's Avatar
 
Join Date: Mar 2005
Location: Welland, Ontario
Posts: 18,529
Rewards Points: 23,408
Blog Entries: 11
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


I say you can do it. Once you install a new breaker panel all you need to do use a double pole breaker in the panel for the pool and a single pole breaker for your receptacles. Do not hook the pool direct to the line from the house. This is no different than the setup you have now in your house with 240 and 120 breakers in the panel.
What size does the pool need? You must size the breaker in the shed panel to match the specs required by the pool pump. You mention 4-8 amps for the pump so I doubt it should have a 30 breaker protecting it which is what you would have if you connected it direct to the line from the house.
joed is online now   Reply With Quote
Sponsored Links
Advertisement
 
Old 10-12-2016, 03:03 PM   #3
Member
 
Join Date: May 2015
Location: Canada
Posts: 7,785
Rewards Points: 74
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


I dunno the electrical very well, but it sounds pretty typical, with the change joed mentioned.

As far as I'm aware (not I'm most reliable memory) you wouldn't need the 30A master breaker in the secondary panel as its already protected to that level up stream. The pool pump, I'd have hooked up as a regular branch off the secondary panel, like joed mentioned.

I'm in Toronto.

Cheers!
supers05 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 10-12-2016, 06:39 PM   #4
Newbie
 
Join Date: Oct 2016
Posts: 18
Rewards Points: 36
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


Quote:
Originally Posted by supers05 View Post
I dunno the electrical very well, but it sounds pretty typical, with the change joed mentioned.

As far as I'm aware (not I'm most reliable memory) you wouldn't need the 30A master breaker in the secondary panel as its already protected to that level up stream. The pool pump, I'd have hooked up as a regular branch off the secondary panel, like joed mentioned.
Yes, this is correct, the circuit is already protected by a double pole breaker (240V 30A) on the house end at the main panel.

But then it would mean I have to go all the way back to the house to cut power to the pool pump supply. And what if I need to conveniently cut the whole shed power in one urgent flip -- in the unlikely situation the 240V pump starts smelling smoke, starts leaking, or making weird noises behind me while I am in the workshop area of the shed? This might be above-and-beyond what code in some areas require, but the peace of mind would be nicer with second master breaker just for the whole brick shed building.

So there would be a second double-pole breaker on the shed end (what I refer to as a "secondary master breaker"). This is useful to cut power to the whole shed at once without going all the way back to the house, including needing to work on pool electricals. And also safety/emergencies too. Water and electricity, you know.

So what I already wrote, involves two double-pole breakers on both ends of the 240V 30A run between buildings. Superfluous to have both for from POV of protecting the wire from overcurrent, so it's for convenience/emergency/other safety -- as a master breaker switch for both voltages for the whole shed.

(I will also need to comply with code, for other things like distance between panel and pool pump, and other code issues.... Researching this too.)

Last edited by mdrejhon; 10-12-2016 at 07:05 PM.
mdrejhon is offline   Reply With Quote
Old 10-12-2016, 07:20 PM   #5
Newbie
 
Join Date: Oct 2016
Posts: 18
Rewards Points: 36
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


Researching further, I figured out what will bring this into code compliance for 120/240V sharing.

A small 8-breaker subpanel enclosure with master switch (or 30A subpanel breaker).

- Only four breaker slots will need to be used up
- I'd install a 240V 15amp GFCI paired breaker for the hardwired pool pump, plus two 120V breakers for the GFCI power outlets.
- Subpanel allows me to add more breakers later (e.g. Pool heater pilot flame ignition, shed lighting, etc)

- Master switch will allow whole shed to be powered off as needed
- I can limit pump to 15A, as its maximum draw is 11A peak (surge/max) with nominal 3A in common low-power mode use.
- I can preserve my existing 120V GFCI power outlets

And the 30amp breaker at the house will protect if the shed ever has too large an electrical load (e.g. someone runs two ceramic heaters plus running the pool pump simultaneously, for example)

Next step: Verify wiith an electrician!

Last edited by mdrejhon; 10-12-2016 at 07:35 PM.
mdrejhon is offline   Reply With Quote
Old 10-12-2016, 07:22 PM   #6
Super Moderator
 
joed's Avatar
 
Join Date: Mar 2005
Location: Welland, Ontario
Posts: 18,529
Rewards Points: 23,408
Blog Entries: 11
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


Now you are understanding what I have been telling you.
joed is online now   Reply With Quote
Old 10-12-2016, 10:01 PM   #7
Member
 
Join Date: May 2015
Location: Canada
Posts: 7,785
Rewards Points: 74
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


I forgot to mention the gfci. I'm glad that you found it.

Another thing I've remembered; Everything electrical that's connected to the pool system in any way, or a certain distance from the pool (not sure what that is though) needs to be bonded to ground.

Even our general purpose heating boilers need to be bonded now.

PS. When you do get a(nother?) pool heater, consider replacement part availability. We just had one under warranty need to have the heat exchanger replaced. 6 week delivery..... They are special heat exchangers.

Cheers!
supers05 is offline   Reply With Quote
Old 10-13-2016, 04:36 AM   #8
MEASURE ONCE, CUT TWICE
 
123pugsy's Avatar
 
Join Date: Oct 2012
Location: MARKHAM, ON
Posts: 4,049
Rewards Points: 1,262
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


If you back feed a 2 pole breaker as you sub cut off, you need a warning label stating the panel is still live and power should be cut off at the main panel in house before servicing.
ESA inspector asked for this recently on my garage panel.

In Ontario, if you are the home owner, you are allowed to do the work yourself.
The person doing the work must pull the permit.
__________________
Pugsy...my project: http://www.diychatroom.com/f49/total...storey-276978/
123pugsy is offline   Reply With Quote
Old 10-13-2016, 08:15 AM   #9
Member
 
Join Date: May 2015
Location: Canada
Posts: 7,785
Rewards Points: 74
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


Quote:
Originally Posted by 123pugsy View Post
If you back feed a 2 pole breaker as you sub cut off, you need a warning label stating the panel is still live and power should be cut off at the main panel in house before servicing.
ESA inspector asked for this recently on my garage panel.

In Ontario, if you are the home owner, you are allowed to do the work yourself.
The person doing the work must pull the permit.
You mean if the panel isn't designed as a service panel with a master breaker in it already? Where you add the breakers to feed into the bus bars? I can see why they want that. I never thought about it though.

Cheers!
supers05 is offline   Reply With Quote
Old 10-13-2016, 10:42 AM   #10
Newbie
 
Join Date: Oct 2016
Posts: 18
Rewards Points: 36
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


Quote:
Originally Posted by supers05 View Post
You mean if the panel isn't designed as a service panel with a master breaker in it already? Where you add the breakers to feed into the bus bars? I can see why they want that. I never thought about it though.

Cheers!
We'll endeavour to find a subpanel whose master switch is also a 240V 30A master breaker. The shed's equivalent of the house's 200A master breaker.

Since the main house panel also protects the subpanel, the shed master breaker could just be a mechanical switch instead (not a breaker). But I'd prefer it if the master switch acted as a breaker...

The view I now understand fully -- is the shed essentially has its own "electric service" from a wiring point of view -- just that the main house is feeding the shed (not the electric company). As the shed equivalent of the main house's 240V 200A service, shed gets wired up as if it's getting a 240V 30A "service".

And I can add new breakers legally anytime I need a new circuit for either 120V or 240V, whether for water sprinkers or lighting (those are very low power draws...).

Thanks for the clarifications, everyone. Far fewer questions I will need to overload the electrician with.

Last edited by mdrejhon; 10-13-2016 at 11:02 AM.
mdrejhon is offline   Reply With Quote
Old 10-13-2016, 11:49 AM   #11
Newbie
 
Join Date: Oct 2016
Posts: 18
Rewards Points: 36
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


Ok, it looks like I probably need two separate boxes. Small subpanels usually don't include a master switch.

A 30amp Safety Switch, and a common 8-slot or 12-slot subpanel box (that can use the same circuit breakers the main house panel uses). I need a 240V 30A junction box to move the panel a few feet further (a meter or two), but that can be a Safety Switch box instead.

Last edited by mdrejhon; 10-13-2016 at 11:55 AM.
mdrejhon is offline   Reply With Quote
Old 10-13-2016, 12:22 PM   #12
MEASURE ONCE, CUT TWICE
 
123pugsy's Avatar
 
Join Date: Oct 2012
Location: MARKHAM, ON
Posts: 4,049
Rewards Points: 1,262
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


Quote:
Originally Posted by supers05 View Post
You mean if the panel isn't designed as a service panel with a master breaker in it already? Where you add the breakers to feed into the bus bars? I can see why they want that. I never thought about it though.

Cheers!
Yes, that is what I was referring to.
__________________
Pugsy...my project: http://www.diychatroom.com/f49/total...storey-276978/
123pugsy is offline   Reply With Quote
Old 10-13-2016, 02:38 PM   #13
A "Handy Husband"
 
rjniles's Avatar
 
Join Date: Feb 2007
Location: South Carolina Low Country
Posts: 9,775
Rewards Points: 582
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


Quote:
Originally Posted by mdrejhon View Post
Ok, it looks like I probably need two separate boxes. Small subpanels usually don't include a master switch.

A 30amp Safety Switch, and a common 8-slot or 12-slot subpanel box (that can use the same circuit breakers the main house panel uses). I need a 240V 30A junction box to move the panel a few feet further (a meter or two), but that can be a Safety Switch box instead.
No way do you need 2 devices. Here is an idea for you.

https://www.homedepot.ca/en/home/p.6...000671510.html

Or use a panel without a main breaker (called a main lug panel) and install a backfed breaker.
I would let your electrician figure out the nuts and bolts.
__________________
My electrical answers are based on 2014 NEC, you may have local amendments.

Location: Coastal South Carolina
rjniles is online now   Reply With Quote
Old 10-13-2016, 02:53 PM   #14
Super Moderator
 
joed's Avatar
 
Join Date: Mar 2005
Location: Welland, Ontario
Posts: 18,529
Rewards Points: 23,408
Blog Entries: 11
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


The master breaker in the sub panel does not need to be 30 amp. It can be 200 amp if you like. It is only being used as a master switch. The 30 amp breaker in the main panel protects the #10 cable feeding the shed.
joed is online now   Reply With Quote
The Following User Says Thank You to joed For This Useful Post:
rjniles (10-13-2016)
Old 10-14-2016, 12:17 PM   #15
Newbie
 
Join Date: Oct 2016
Posts: 18
Rewards Points: 36
Default

Re: [Canada Code] Sharing 240V and 120V appliance on same circuit in workshop shed?


Quote:
Originally Posted by rjniles View Post
No way do you need 2 devices. Here is an idea for you.

https://www.homedepot.ca/en/home/p.6...000671510.html
That's a bit overkill, but an option!
A 16/32-circuit panel will look quite massive with only 3 breaker slots filled, possibly 4th for heater (with foreseeable future fill of 1 more later).

But at only $70 it's cheaper than two boxes. That said, weighing the pros/cons -- wall space is valuable and we need to maximize (shelving, tools, etc). The backfeed is an option.

Still need that 240V 30A junction box though, as the wire coming out of the ground is 1-to-2 meter too short to reach where I want to locate the main breaker panel.

Yes, I would let an electrician figure out the nuts and bolts. I have the skills to install a subpanel myself, but not the knowledge of code to confidently solve all nuances (e.g. electric code catches; how far away panel must be from the pool pump, other gotchas). I just want to reduce electrician costs as much as possible as I have already installed some of the circuits myself (the GFCI outlets, lighting), and installed new breakers in the main panel.

Last edited by mdrejhon; 10-14-2016 at 12:20 PM.
mdrejhon is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Can GFCI circuit breaker handle combined 240V and 120V circuits? muncheroo Electrical 9 04-13-2013 12:02 PM
Power 120V Pump from a 240V circuit RoberTX Electrical 26 07-05-2011 11:43 PM
Two 120v Nuheat mats wired in series for 240v circuit? chrispy35 Electrical 18 04-26-2010 11:16 PM
Pulling 120V outlet from a 240V circuit? npage148 Electrical 12 11-08-2009 11:29 AM
120v for shed from 240v HotTub circuit? MrMark Electrical 6 04-06-2009 12:43 AM




Top of Page | View New Posts