I want to wire a bath room up flush toilet which is 5.3 amps motor into a curicuit with a 1500 watt wall heater ( 13 amps) on a 120 -20 amp breaker . The heater is never on and the toilet would only come on when some one uses down stairs bathroom.

While your plan will work, since the heater never is used, a future occupant will have problems with the CB tripping if both devices are used.

If the heater is never used, remove it if not needed.

Better to install a circuit for the pump if at all possible.

While your plan will work, since the heater never is used, a future occupant will have problems with the CB tripping if both devices are used.

If the heater is never used, remove it if not needed.

Better to install a circuit for the pump if at all possible.

Thanks , the bathroom is a extra if someone sleeps over in spare room in basement. To keep them from running upstairs all the time at night. The heater only gets used if its winter and the wood stove or electric heaters aren't on.

The pump for these flush up toilets usually run for about 30 seconds when the toilet is flushed. The total load is about 19 amps on a 20 amp breaker for 30 seconds. This should be trouble free, even if the heat is on. Run the heater for a while then flush the toilet, does it trip he breaker? Enough said.

tk:
1200/120 * 1.25 = 15.625 because it's space heating
20 * 0.8 = 16; 15.625<20; so 20 amp breaker is appropriate.

Add 5.3 and it's over 20 A.

My analysis:

20 A 12 awg circuit for heater,
15 , 14 awg circuit for pump.

Correct?

For this circuit to be undersized the continuous load (over three hours)would have to be in excess of 16 amps. That's clearly not the case.

Herman, the Code is very specific about electric space heating circuits, as that they shall be considered as a continuous load, as per Article 424, Section 424.3(1) (B), and shall be sized 25% higher than the running load of the heat.

This is not a general purpose lighting circuit, but a circuit dedicated for fixed electric space heat.

Motor circuits shall be sized as per Article 430.

Since the existing 20 amp circuit was for a space heater, that circuit is now sized just right for that heat, as shown by Kiss's calculations.


Since the circuit can, or hopefully, be used for one OR the other, no problem.

If both get used, the circuit now does not comply with Code.

In practical terms, sure I agree that MOST times, if both are running, there may not be an operational issue. I, however, will not offer that advice, as if I were to do the installation in this manner based on a practical possibility, I could not insure any problems in the future.

Therefore, for a Code compliant installation, and one I will never need to worry about, both devices need their own separate circuit.

When you are right, you are right. And you are right. When someone is right I will always say so. (( However I will now mumble -- but as a practical matter... ))

Oh, believe me, I get it,


(( However I will now mumble -- but as a practical matter.....))

This was my initial instinct also.

But if code is specific, and once we leave a job, and if we just don't know what will be done, I have been told so many times 'I will not run both" or whatever the situation, never fails, I get the call that what I did is not working, and off I go to install what I should have in the first place, no matter what the customer tells me.

Now, in this venue, dealing with DIY'ers, we need to be even more vigilant with the best, accurate advice as possible.

Better to be safe than sorry.

Yea, I have issues too that would not meet code, BUT some make sense and some should be changed.

1st. Still have fuses with a few Mini-breakers. No GFCI's in the bathroom, but the only thing used there is a hair dryer with a built-in GFCI and a toothbrush (totally sealed). A sweeper is plugged in that location because there is no easy accessible outlet in a hallway. Bathroom shares a circuit.

No GFCI's in the kitchen.

GFCI's were added for the porch/room and front outdoor receptacle.

I also have an outdoor light in the attic which is not technically outside. It's on only when someone is up there. It sure beats a couple of 60 W bulbs. CFL's take too long to warm up in the cold.

There are still a few 2 prong polarized plugs left. Changed as they had to be.

2 years ago I painted a bedroom and I replaced all of the 2 prongs with tamper proof Decora 3 prongs. I also put in a low voltage wall plate unwired. The opportunity was there, so I took it.

Insuring a house with fuses is difficult unless you already have a policy so if the house was sold a service upgrade would probably have to be done.

House is about 50 years old. Some things, of course, grandfathered.