Electrical Safety.

lazybean · 10-06-2009, 06:12 PM

I just wanted to post a few basic electrical safety items. The National Electical Code (NEC) has a zillion rules and exceptions, 772 pages worth, so i am not going to get into to much depth. Most of the advise in here is spot on, i just weanted to clear up a few things.

First: GFCI must be used on all outdoor, garage, bathroom, kitchen, and basement outlets of any size. This is the single biggest safety item you can install. There are three ways to install a GFCI; Circuit Breaker, Outlet, and Plug-in. CB and outlets are installed permanently into your house wiring, Plug-in is portable, looks like a 2' extention cord with a little molded box in the middle. they can be found at RV supply and some home supply stores. How they work

Second: Grounding The purpose of grounding (Equipment Grounding) is to give stray currant a path back to the supply to facilitate the tripping of over-current or Ground fault devices. This simple mean that if there is a short, the equipment ground is the electrical path not you. everything metal that is connected to something electrical needs top be grounded.

Third: Over-Current Protection These are the devices that prevent too much electrical current from flowing through wires and equipment. NEC table 310.16 list how much amperage a given wire size can handle, you must have a fuse or circuit breaker at or smaller then that number. This mean if you supply your Brewery Control box with a 50amp 120/240v CB, and tap off a 120v 15a outlet for pumps or relays, they must have a 15a fuse/CB protecting them. This is to prevent that little 15a outlet and 14awg wiring from overheating do to a potential 50amp current. A GFCI will not prevent this! Edit: After talking to engineer(UL code), he stated that if you are using Heater elements hard wired or Cord and plug connected greater then 1500w, each element must have its own set of fuses, unless thermally protected.

I am an Electrcial Contractor in California, I do Industrial and Commercial work, so feel free to ask me anything related.

JKoravos · 10-06-2009, 09:36 PM

Great post. Don't screw around with electrical unless you know what you're doing. If you don't know what you're doing, find someone who does, or do A LOT of research and ask questions of people who do know what they are doing...aka lazybean

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**Bernie Brewer** · 10-06-2009, 10:19 PM

Quote:

Originally Posted by lazybean

I just wanted to post a few basic electrical safety items. The National Electical Code (NEC) has a zillion rules and exceptions, 772 pages worth, so i am not going to get into to much depth. Most of the advise in here is spot on, i just weanted to clear up a few things.

First: GFCI must be used on all outdoor and garage outlets, of any size. This is the single biggest safety item you can install. There are three ways to install a GFCI; Circuit Breaker, Outlet, and Plug-in. CB and outlets are installed permanently into your house wiring, Plug-in is portable, looks like a 2' extention cord with a little molded box in the middle. they can be found at RV supply and some home supply stores. How they work

They are also required in bathrooms, basements, and kitchen and dining room countertops. All of these areas, with the possible exception of bathrooms, are possible brewing areas, so if you brew with electricity, make sure the circuit you use is GFCI-protected.

Good post, BTW

wihophead · 10-06-2009, 10:56 PM

The problem I see pointing people to table 310.16 is that I would bet most people do not no how to use it, much less know anything about derating and correction factors.

I could see someone looking at the table and not notice the * that points you to 240.4(D) which states that the maximum OCP shall not exceed 15A (with some exceptions of coarse)and assume 14AWG THHN is OK for 25A
Or 8AWG THHN is OK for 55A when most likely it is OK for 50A but may only be good for 40A if the terminations are rated for 60C.

Oh and that table doesn't even cover cords......

**arturo7** · 10-06-2009, 11:03 PM

Thanks for posting that. I need to look into the over-current protection.

**samc** · 10-06-2009, 11:12 PM

Quote:

Originally Posted by lazybean;1592220

[B

Third[/B]: Over-Current Protection These are the devices that prevent too much electrical current from flowing through wires and equipment. NEC table 310.16 list how much amperage a given wire size can handle, you must have a fuse or circuit breaker at or smaller then that number. This mean if you supply your Brewery Control box with a 50amp 120/240v CB, and tap off a 120v 15a outlet for pumps or relays, they must have a 15a fuse/CB protecting them. This is to prevent that little 15a outlet and 14awg wiring from overheating do to a potential 50amp current. A GFCI will not prevent this!

Thanks for the post. Sounds like I may be violating that rule. I have my control panel fed by 20 amp circuit. That feeds 1500 watt heater element in RIMS and 2 pumps plus a BCS control box. Are you saying that I need to have fuses on the pumps and control box and if so what size should they be as those devices are very low amp draw?

**Bernie Brewer** · 10-06-2009, 11:24 PM

Quote:

Originally Posted by samc

Thanks for the post. Sounds like I may be violating that rule. I have my control panel fed by 20 amp circuit. That feeds 1500 watt heater element in RIMS and 2 pumps plus a BCS control box. Are you saying that I need to have fuses on the pumps and control box and if so what size should they be as those devices are very low amp draw?

No, you do not, as long as you are using 12 gauge wire. It is the wire and the receptacles that the fuses/breakers are for, not the equipment that you are powering.

You do, however, need a disconnecting means for your element and pumps. A cord and plug is acceptable.

**HBHoss** · 10-06-2009, 11:37 PM

Good and timely information since I'm in the process of wiring my nanobrewery. Thanks for posting this.

OLDBREW · 10-07-2009, 12:38 PM

Quote:

Originally Posted by samc

Thanks for the post. Sounds like I may be violating that rule. I have my control panel fed by 20 amp circuit. That feeds 1500 watt heater element in RIMS and 2 pumps plus a BCS control box. Are you saying that I need to have fuses on the pumps and control box and if so what size should they be as those devices are very low amp draw?

in residential apps your amperage calculations shouldn't exceed 80% of branch circuit

residential wiring, a 14 gauge wire is not to exceed 15 amps. A 12 gauge wire is not to exceed 20 amps although both gauges can handle more amps.

so if you look at a 20 amp residential circuit, you would take the voltage, then multiply that by amps to give you watts.

20 * 120 = 2400 @80% 1920 watts max.

heating elements can be formulated at 100% of there load so 1500 watts

motor loads have to be calculated @ 125% of their amp draw

some of the march pumps we use are .7 amps so .7 * 120 = 84 watts * 1.25 = 105 watts x 2 motors = 210 watts.

1 element 1500w
2 motors 210w

1500 + 210 = 1710 watts

1920 - 1710= 210 watts under your maximum allowable load without the controller load??

are your pumps rated at .7 amps, and what is your controller rated at?

sjlammer · 10-07-2009, 01:21 PM

I struggled with how to account for three within my control box (in process).

I have 50 amps coming in to a distribution block, and then splits out to one 30 amp and several different 20amp circuits (which will not all run simultaneously).

how do i install over-current protection inside a control panel? I can't use conventional circuit breakers as i don't have a way to mount them?