The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Sprinklered equipment 26-008
by bigpapa
12/02/16 04:24 PM
On Delay Relay with Auto Reset
by Potseal
12/01/16 09:59 AM
Wow, that was close!
by jraef
11/28/16 07:06 PM
Earthquake in New Zeeland
by RODALCO
11/27/16 11:25 PM
Calling all Non-US members!! (Non-US only)
by Tjia1981
11/27/16 06:33 AM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 14
HotLine1 10
Trumpy 8
Texas_Ranger 8
sparkyinak 7
Who's Online
0 registered (), 198 Guests and 5 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#30642 - 10/23/03 10:15 PM 2 loads sharing 1 breaker.
aldav53 Offline
Member

Registered: 08/22/01
Posts: 547
Loc: Chandler, AZ USA
Estimated a job installing a car lift. The panel is full but I could tie into the balancer machine in a junction box feeding it. It is the right size circuit too. The manager said they would never use both at the same time. Is this legal?
_________________________
The Golden Rule - "The man with the gold makes the rule"

Top
Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#30643 - 10/24/03 05:47 PM Re: 2 loads sharing 1 breaker.
Pinemarten Offline
Member

Registered: 08/23/03
Posts: 122
Loc: Edmonton, AB, Canada
In Canada, I think it is allowed if you install a transfer switch, so only one unit can be used at a time.
Is it easier to put in a sub-panel to create breaker space?

Another solution is to install one receptacle and put a cord end on each unit. They would only be able to connect one at a time.
They may 'promise' not to use both at once, but make sure they are incapable; otherwise they may just put in a bigger breaker after you leave.

Is the new unit a long way from the panel?

Top
#30644 - 10/24/03 08:55 PM Re: 2 loads sharing 1 breaker.
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
aldav53,
What sort of current are we talking here, between the 2 loads?.
What size/type breaker protects these 2 circuits?.
Normally there shouldn't be a problem, unless the breaker trips and the car-lift loses pressure.
Is there any way that you can install a Sub-Panel, from the Main Panel?.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

Top
#30645 - 10/25/03 01:05 AM Re: 2 loads sharing 1 breaker.
wireman Offline
Junior Member

Registered: 10/24/03
Posts: 9
Loc: state of washington
To start with, you will need to meet the requirements in section 210.23

You really have not given enough info to determine if the installation is legal. I suspect it is not, if you are worried about them using both pieces of equipment on the same circuit.

What about a "mini" breaker? If a mini will work you should install a separate neutral.

Top
#30646 - 10/25/03 06:41 AM Re: 2 loads sharing 1 breaker.
aldav53 Offline
Member

Registered: 08/22/01
Posts: 547
Loc: Chandler, AZ USA
It is a 20 amp 208 volt 2 pole circuit. They don't make a mini breaker for a bolt in type. If the breaker tripped the hoist would not lose pressure. The panel is a fair distance away and so is the hoist from the balancer. If they did run them at the same time the circuit would probably hold it, (I will check the amp draw on the balancer).
I don't think there would be a problem, as long as it is code compliant.
_________________________
The Golden Rule - "The man with the gold makes the rule"

Top
#30647 - 10/25/03 10:53 PM Re: 2 loads sharing 1 breaker.
wireman Offline
Junior Member

Registered: 10/24/03
Posts: 9
Loc: state of washington
Ok, more information is good.
If you intend to feed both pieces of equipment from the 20a breaker then your combined load will be the key. You should be able to find the amps on the nameplates of the equipment in question.

I would not install both pieces of equipment on the same circuit if their combined load exceeds the load allowed, by the NEC. It is legal to install multiple pieces of equipment on a given circuit, but the installation must meet the requirements of the NEC. The managers word about equipment useage - is not an exception to the NEC or a disclaimer for possible injury to people and damage to property.

Top
#30648 - 10/30/03 08:32 AM Re: 2 loads sharing 1 breaker.
SJT Offline
Member

Registered: 07/24/02
Posts: 242
Loc: PATCHOGUE, N.Y.
I had recently done a lift. It was the kind that the car was elevated off the ground by a cable/ hydraulic unit. It wasn't the old big tube in the ground type. The lift had a contactor (3 phase) and we needed to have a circuit ran to it. I would reconmend a line by itself, just for the lift. There is a lot of weight involved and a guy stands under the car to work. Why take a chance?

Top
#30649 - 10/30/03 07:05 PM Re: 2 loads sharing 1 breaker.
aldav53 Offline
Member

Registered: 08/22/01
Posts: 547
Loc: Chandler, AZ USA
Those old ones work on air pressure I believe. This new one uses an electric motor to raise and lower, so if power is off it won't go down.
_________________________
The Golden Rule - "The man with the gold makes the rule"

Top
#30650 - 10/31/03 04:22 PM Re: 2 loads sharing 1 breaker.
Speedy Petey Offline
Member

Registered: 08/29/03
Posts: 175
Loc: Upstate, NY
"There is a lot of weight involved and a guy stands under the car to work. Why take a chance?"

Chance of what??? All lifts have safety cams to prevent them dropping and this has nothing to do with the electrics.

Do exactly as Wireman said, if the combined load is within the 80% of the breaker's rating. This could be considered a non-continuous load since a tire balancer or lift theoretically could never be used for 3 hours straight. I would still stay under the actual rating of the breaker.
_________________________
Speedy Petey

"Anyone who has never made a mistake has never tried anything new." -Albert Einstein

Top
#30651 - 10/31/03 04:30 PM Re: 2 loads sharing 1 breaker.
aldav53 Offline
Member

Registered: 08/22/01
Posts: 547
Loc: Chandler, AZ USA
Speedy,
That makes good sense.
_________________________
The Golden Rule - "The man with the gold makes the rule"

Top



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals