240/120 on same circuit

[Mike1903]

When we run a 3 wire + ground conductor, I see that two hots are used for 240v needs and one hot/neutral is used for 120v needs as the bulb. This is how electric dryers are set up (afaik).

Can the same be done for multiple loads? For example, I was planning to run 30a circuit to gazebo for infrared heater. Can I add lights, fan and outlets on the hot/neutral for 120v? I realize I need to provide GFCI protection for 120v side but wanted to see if one circuit can suffice.

if it is a code violation, can you please explain why?

thanks

 

[mike93lx]

You want to put 15 or 20a 120v outlets on a 30a circuit? Yes, that would be a violation without additional over current protection.

A small subpanel sounds like the right answer

 

[Mike1903]

You want to put 15 or 20a 120v outlets on a 30a circuit? Yes, that would be a violation without additional over current protection.

A small subpanel sounds like the right answer

Thank you! Simple but elegant explanation…

 

[larry4406]

But to the OP’s example/question, the 120V light bulb in the dryer is being fed from (likely) a 30A 240V breaker. How is this then safely done? Or do we just look away since the dryer is a UL listed device (black box)?

 

[Norcal]

But to the OP’s example/question, the 120V light bulb in the dryer is being fed from (likely) a 30A 240V breaker. How is this then safely done? Or do we just look away since the dryer is a UL listed device (black box)?

Electric ranges are the same, smaller conductors but the insulation is rated for a higher temperature, in the past if nobody monkeyed with the wiring it was pretty much trouble free, now not so sure.

 

[mike93lx]

But to the OP’s example/question, the 120V light bulb in the dryer is being fed from (likely) a 30A 240V breaker. How is this then safely done? Or do we just look away since the dryer is a UL listed device (black box)?

Guessing there is some OCP in the dryer

 

[Norcal]

Guessing there is some OCP in the dryer

Nope, when convenience receptacles used to be a thing on ranges, there was a fuse for it.

 

[Bert_]

Inside of an appliance it's easy to determine what the load is. The light only pulls 1 amp so we can run small wire to it even though the whole appliance is on a 30.

Out in the world it's not so easy. There's no way to prevent someone from plugging in more than 15 or 20 amps on a 120 volt receptacle.

 

[Terry D]

When we run a 3 wire + ground conductor, I see that two hots are used for 240v needs and one hot/neutral is used for 120v needs as the bulb. This is how electric dryers are set up (afaik).

Can the same be done for multiple loads? For example, I was planning to run 30a circuit to gazebo for infrared heater. Can I add lights, fan and outlets on the hot/neutral for 120v? I realize I need to provide GFCI protection for 120v side but wanted to see if one circuit can suffice.

if it is a code violation, can you please explain why?

thanks

There are separate rules for tapping branch circuits and feeders. What you are talking about doing here is tapping a branch circuit, which falls under 210.19(A)(4) exception (1) covers what loads can be tapped . (c) covers what you are talking about. Individual outlets, other than receptacle outlets, with taps no longer than 18 inches are allowed. So no receptacles are not allowed since they are not listed in the exceptions.

As far as the dryer having 120 tapped off of 240, As long as that appliance is listed for that purpose, there is no violation. Starting with the 2017 NEC 422.6 All appliances operating at 50 volts or more shall be listed.

 

[wyliesdiesels]

When we run a 3 wire + ground conductor, I see that two hots are used for 240v needs and one hot/neutral is used for 120v needs as the bulb. This is how electric dryers are set up (afaik).

The motor and controls in the electric dryer are also 120v...

Can the same be done for multiple loads? For example, I was planning to run 30a circuit to gazebo for infrared heater. Can I add lights, fan and outlets on the hot/neutral for 120v? I realize I need to provide GFCI protection for 120v side but wanted to see if one circuit can suffice.

if it is a code violation, can you please explain why?

thanks

no you cannot. your comparing internal wiring in an appliance that is listed by an NRTL and most likely has higher temperature rated wire and a load that is fixed and predictable (light and motor), to inside wiring in a building, feeding outlets, that would have no control over how much load is plugged into it up to 30a.... thats a recipe for a fire.... and a flawed comparison...

But to the OP’s example/question, the 120V light bulb in the dryer is being fed from (likely) a 30A 240V breaker. How is this then safely done? Or do we just look away since the dryer is a UL listed device (black box)?

A light bulb is a fixed load. Its not gonna pull more than its rated current. just like plugging in a 100w lamp, with an 18gauge cord, to a 15a or 20a circuit.... really the same concept...