DARKROOM - Electric Questions

[Salmo22]

Great comments all, please keep them coming. I forgot to mention that HAVC is already serving this pantry space will sized fine for the small expansion. I also will be installing two exhaust fans over the custom sink.

[Salmo22]

I'm not clear on what you mean with respect to the 220v outlet and converting it to 120v. Ya you could split it to two 120 breakers, but if that outlet was for a 50 amp welder circuits that would mean your feed wires would be huge 6 gauge cable. Best thing to do is either leave the 220v alone and put in new additional breakers with dedicated new romex runs, or take out the 220 breaker and outlet and use the existing wire to pull new romex through. 6 gauge wire is hard to work with, is not something you need and mixing cable sizes on a circuit is bad practice.

Side note- the 220v outlet in a garage would be really useful for an Electric Vehicle charger if you ever intend to upgrade your car.

I built and wired this house 38 years ago. I did all the 20 amp circuits with 2/12/ground. It is a pain to make up the boxes and trim out, but I like big copper.

Unfortunately, the 220v has a 50 amp breaker and is 6 gauge copper. Like the rest of the house, I pulled that one homerun myself. What I'm hoping to avoid is extending existing circuits and create possible problems with overload. Thus, I was hoping to pirate the 220 as is service nothing but that single welder outlet. It has been nearly four decades since I wired this house, so I'm open to ideas.

[Salmo22]

move the safelight and fan switches away from the other switches, you don't want to mix those up.

Terrific suggestion - thanks.

[Salmo22]

All depends on if you might hypothetically scale up to higher voltage or higher wattage equipment further down the line, especially if you contemplate something like 8x10 color enlarging. It's easier to bring in 240 voltage early on, rather than retrofit. But 20A 115 is ample for what you currently have in mind. I'm personally nitpicky about getting good quality CFCI outlets and breakers from reputable electrical supply houses, and not from the usual Cheapo Depot type suspects - it really can make a huge difference in reliability. Likewise lighting. But any kind of wattage glutton like routine air conditioning will be way less expensive if run on a dedicated 240 V circuit.

4x5 black and white printing is as big as I'll get. No color for me. So the Beseler 45V-XL will likely outlast me. As I noted, it is possible I'll convert to a cold light LED source somewhere down the road, but that doesn't seem to be an issue. What brand of CFCI outlets and breakers to your recommend?

[Salmo22]

If any of you would be willing to share photos of your darkrooms with me, I'd be most appreciative. PM me if you'd rather not post here and I'll get you my email address.

[Salmo22]

Assuming that you are the only person using your darkroom...you can split that 220 circuit into two 120's...and dedicate one of those to just your enlarger bench. In other words...no other uses for that circuit. Then, the remaining 120 can be dedicated to everything else in the darkroom, helping to ensure minimal interference with line voltage on your enlarger circuit...which is very important!

Do be careful that various devices which employ heating elements (film dryers, dry mounting presses, electric room heaters), should all be isolated from your enlarger circuit!

I also happen to own a Heiland VC LED head for my Zone VI enlarger...and so far its been extremely consistent in output, without the employment of any additional voltage stabilization scenario, excepting the aforementioned enlarger circuit isolation. I do have a voltage stabilizer for my Beseler 4x5 enlarger...but really don't use that enlarger all that much since the acquisition of my Zone VI.

And yes...normal 125 volt gfci's will be fine for your darkroom, and, if below grade (typical for a home basement) likely required by your local electrical code. The only exception would be if you were using electric motors with high starting torques (like a large diameter chop saw) - which can throw a gfci on those occasions when other outlets in that circuit are also in current (ha!) use. Not a likely scenario in your darkroom.

Having one of the new 120 circuits dedicated to my enlarger bench is a terrific idea.

[Eric Woodbury]

I can send some photos later.

Take your 50A circuit and put a subpanel there. Maybe a 4 position or 6 position box. Then with surface plastic conduit, make everything just right.

My DR has 4, 20A breakers. 1 for heat/AC, 1 for all the lighting, 1 for all the non-lighting, and 1 for general stuff. Then I have outlets up high for safelights. Track lighting has a pull-string switch. If I want to load film, then I OFF the lighting circuit. If I need the heater or AC on, I flip that switch. Outlet cover plates are color coded so I know which outlet goes to which switch. Oh, I don't use the breaker for switches. The subpanel is in another room as it services many other things in the building. But those four circuits come to GFI outlets and then 3 of them to normal 20A wall switches. The general stuff circuit, doesn't have a switch.
It is the stereo, film fridge, clock, ... that kind of stuff.

GFI breakers are expensive and if you get a leak in your circuit, it can be very difficult to trace.

When I leave the darkroom, I OFF all the switches. I've known too many photogs that have had electrical fires in their DR. How many is too many -- more than zero. Two actually.

Hope this makes a little sense.

[Salmo22]

I can send some photos later.

Take your 50A circuit and put a subpanel there. Maybe a 4 position or 6 position box. Then with surface plastic conduit, make everything just right.

My DR has 4, 20A breakers. 1 for heat/AC, 1 for all the lighting, 1 for all the non-lighting, and 1 for general stuff. Then I have outlets up high for safelights. Track lighting has a pull-string switch. If I want to load film, then I OFF the lighting circuit. If I need the heater or AC on, I flip that switch. Outlet cover plates are color coded so I know which outlet goes to which switch. Oh, I don't use the breaker for switches. The subpanel is in another room as it services many other things in the building. But those four circuits come to GFI outlets and then 3 of them to normal 20A wall switches. The general stuff circuit, doesn't have a switch.
It is the stereo, film fridge, clock, ... that kind of stuff.

GFI breakers are expensive and if you get a leak in your circuit, it can be very difficult to trace.

When I leave the darkroom, I OFF all the switches. I've known too many photogs that have had electrical fires in their DR. How many is too many -- more than zero. Two actually.

Hope this makes a little sense.

Thanks Eric for your suggestions. I like the idea of a 4 position subpanel box.

[martiansea]

Are GFCIs really necessary for the wall with the enlarger? Those are intended for ground faults caused by an appliance falling in water. They're required for outlets near water, but otherwise unnecessary. Have them by the sink of course, but just there. I think the enlarger would be happier without it.
I would upgrade the enlarger to some kind of LED light source right away, before even setting it up to use. No point in fooling with the old technology anymore. Do everything possible to minimize the energy required to run everything. Make it so the heater in the Jobo is the neediest thing. Since you're building the room up new, this is the attitude I would take.

[Eric Woodbury]

GFIs are cheap and provide great protection. Required most everywhere there is exposed ground, earth ground, bare slabs, metal pipes. All damp locations, garages at or below grade, etc. Also within 4' of a door that leads immediately to outside (so that when you're outside and need some power, you don't open the door and get unprotected power).

You are allowed to put a GFI on an old two wire circuit for remodels (no earth or U-ground previously available). This is an easy way to get that third hole in homes that have older wiring. Also, altho you can cascade GFIs, this leads to confusion when there is a fault, so best not to do so.

Your enlarger nor any other piece of equipment won't know the GFI is in place. GFI work on the idea of balanced current. The feed and return wires go through a toroid such that the current to the load vs the current on return can be monitored with the magnetic field. Cute trick. The toroid is not in the circuit to the load.

"Old technology" ... that's what darkrooms are. LED light sources are a lot of fun and very efficient with power, but a cold light is very efficient with power too. Neither are ON very much, so the total output energy is low.