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Amperage question for electrician types

Thread starter #1

Radogast

Grow Journal of the Month: April 2017
I was recently told my flower room 20 AMP service is insuffient.

- - -

My flower room has a dedicated 20AMP breaker, about 40 feet of grounded 12/2 Romex wiring, and 3 outlet boxes.

The main outlet has a 15AMP/1200W rated digital 2 plug timer. The 2 plugs power two HPS 600W bulbs and associated digital ballasts.

The second outlet has a 6 inch inline fan (Can Fan RS6HO) rated at max 138W, 1.15 AMP. It has a temperature sensor controller switching the inline fan on and off as needed. It also has a 12" oscilating fan on a stick to circulate air.

The third outlet powers a string of mini-christmas lights that I use as a task light. I sometimes use it for general power (shop vac, 216W trimming light.)

I use an extension cord for the oscilating fan. Otherwise, there are no power strips or extension cords.

That's it.

- - - -

I have been up and running for about 1.5 years. I recently had a ballast "in the shop" at a local store because it was flashing over voltage. The problem was diagnosed as a 1 year old HPS bulb asking for too much amperage. During the discussion I was told I should have my 600W HPS on seperate 20 amp circuits because they can draw much more that 600 watts during startup.

I have not had any electrical problems except for this ballast problem, which was resolved with the purchase of a new HPS bulb.

Before I built my veg room, I used to run an additional 432 watts (2x4 bulb T5 CFLs) off the main outlet box.

My digital ballasts have random staggered start delays to reduce the power surge of two 600W HPS starting from the same timer.

- - -

Is the 20 AMP service to my flower room insuffucient ?
 

Highpotanoose

Well-Known Member
See if I can help ease your mind.

Your 2 600 watt lights pull 5 amps each at a 120 volts, 10amps total

Exhaust Fan is 1.15 amps

Circulation fan can't be much ,we will call it 1 amp

Looks like 7.15 amps is your reg equipment which is well under the rated load, should not be a problem

Should have around 10 amps for misc

When you add the shop vac and task lights they deff don't add 10 amps

I see no problem

If you are tripping a 20 amp breaker on the regular then I would add more circuits

You can load a 20 amp breaker to 85% (17amps)of its capacity with no problems

Only thing I would suggest is to add receptacles rated at 1500 watts or higher on your lights

You can legally put 20amp receptacles on your circuit


:Namaste:

Hope that helps brother
 
Thread starter #3

Radogast

Grow Journal of the Month: April 2017
See if I can help ease your mind.

Your 2 600 watt lights pull 5 amps each at a 120 volts, 10amps total

Exhaust Fan is 1.15 amps

Circulation fan can't be much ,we will call it 1 amp

Looks like 7.15 amps is your reg equipment which is well under the rated load, should not be a problem

Should have around 10 amps for misc

When you add the shop vac and task lights they deff don't add 10 amps

I see no problem

If you are tripping a 20 amp breaker on the regular then I would add more circuits

You can load a 20 amp breaker to 85% (17amps)of its capacity with no problems

Only thing I would suggest is to add receptacles rated at 1500 watts or higher on your lights

You can legally put 20amp receptacles on your circuit


:Namaste:

Hope that helps brother
Thank you. I did spend the extra bucks to get 20 amp outlets.

By simple math, I was sure the load was fine, but ... the man at the store usually knows what he is talking about.

Thanks
 

Highpotanoose

Well-Known Member
Thank you. I did spend the extra bucks to get 20 amp outlets.

By simple math, I was sure the load was fine, but ... the man at the store usually knows what he is talking about.

Thanks
Money well spent on the receptacles

Will save you the headaches later
 
All breakers are designed to withstand an inrush current (motor starting). You should be OK. Too late but you could have ran a 12/3 and used a double pole 20a breaker and had two separate 20a feeds, or 40a total ;).