I do not think 427 applies, 427 is for heating pipes themselves. Like heat tracing or impedance heating systems. I doubt the steam generators use electrode type heaters. Electrode heaters run current through the liquid itself to heat it.
I can't imagine why these steam generators would need a GFCI any more than the electric water heater supplying a shower?
[This message has been edited by iwire (edited 05-31-2005).]
Bob Badger Construction & Maintenance Electrician Massachusetts
Re: Steam generator units / showers#93522 05/31/0509:29 PM05/31/0509:29 PM
"I can't imagine why these steam generators would need a GFCI any more than the electric water heater supplying a shower?"
I'm not sure, but I don't think that the average water heater has the elements within the tank? I think they heat the outside of the tank. I haven't broken one open...
Both units mentioned above have the (assuming resistance) elements within the tank, or "vessel". They are also nearly identical units from the same company, and seem to quote out of two different codes in thier instructions?
Now just for the sake of debate, as truthfully I am lost here:(It sounds like either one could apply, but both are very different from eachother!)
ART. 424 Fixed Electric "Space-Heating Equipment" And within its scope covers boilers.And, further on says, "This article shall not apply to process heating..." What-ever that is? Then goes on, and on about space heating and base-board heaters, until you get to part VII. Resistance-Type Boilers. Anyway, to me it sounds more, and more like "boiler" for a radiator, or "space heating" device.
Now 427, Fixed Electric Heating Equipment for Pipelines and Vessels.
"427.1 Scope. The requirements of this article shall apply to electrically energized heating systems and the installation of these systems used with pipelines or vessels or both."
Further in the definitions it has "Vessel". "A container such as a barrel, drum, or tank for holding fluids or other material." (like the one in these units?)
So 424 requires: Disconnect within site of equipment or controler, and in some cases be able to locked open. (No provission for cord connected...) No applicable GFCI requirements. No mention of grounding other than in Electrode types.
And 427 requires: "disconnecting means shall be of the indicating type and shall be provided with a positive lockout in the “off” position." With some provision for cord connected at 20A or less. (simular to some of these units) Requires GFCI protection. And only mentions grounding as part of the electrod or resitance types for the heating methods.
(In terms of bonding metalic pipes "likely to become energized", I have to do that from 250.104(B), for hot water, and gas, everything except waste lines for the time being.)
So which one is it for sure???
Mark Heller "Well - I oughta....." -Jackie Gleason
Re: Steam generator units / showers#93523 05/31/0509:56 PM05/31/0509:56 PM
These things sure can take on a life of their own. Think about it guys. It's a WATER HEATER. Yes it only serves one location in the house but so what? In my house, built in '02 I have an electric water heater in a closet IN THE BATHROOM on the first floor. It's 240 volt, the elements are immersed in the water, the circuit breaker serves as the disconnect and it's not GFI protected because its not 120v. The code does not address each individual piece of equipment. Some judgement is required.
Re: Steam generator units / showers#93525 06/01/0503:15 AM06/01/0503:15 AM
Greg', if a steam unit is a water heater, so is a hot tub. But a hot tub is also a pool of some sort, right? And I have put many/all of them on 240 volt GFCI's. Same as jaccuzi tubs and thier water heaters. As well as the outlets in the bath, and on occassion lighting in shower and tub areas.
And I'm not quoting you to start with you, but... "The code does not address each individual piece of equipment. Some judgement is required."
Exactly! What judgment is to be made?
In all of the instructions of these it says, in words to the effect of... "All electrical wiring to be installed by a qualified licensed electrician in accordance with National Electrical Code and local electrical code." Great, which part of it? I think we all fit the "qualified licensed electrician" part of it, but which code?
One of the ones I listed above states in its instructions, that a GFCI is required by code, again, which code?
In general we could make a judgment on that it is a permantly installed appliance over 300VA: 422.31(B) would apply for disconnect at the very least. _______________________________________
Further judgment : (250.4(A)4, and 5, and 250.104 for the bonding, and the GFI just because...)
I'd put a GFI on it, and bond the the pipes of it. (Like I aways have.) Because you have a situation where you have a naked and wet person in a small damp room with two metallic objects in it. One is a steam outlet, the other a cold water connected to a faucet. Any fault current on the steam outlet could kill, if not be a liability issue.
Commentary from 250.104
Bonding the interior metal water piping system is not the same as using the metal water piping system as a grounding electrode. Bonding to the grounding electrode system places the bonded components at the same voltage level. For example, a current of 2000 amperes across 25 ft of 6 AWG copper conductor produces a voltage differential of approximately 26 volts. Section 250.104(A)(1) requires the interior metal water piping system and any other metal piping systems likely to become energized to be bonded to the service equipment or grounding electrode conductor. If it cannot reasonably be concluded that the hot and cold water pipes are reliably interconnected, an electrical bonding jumper is required to ensure that this connection is made. Some judgment must be exercised for each installation. The special installation requirements provided in 250.64(A), (B), and (E) also apply to the water piping bonding jumper.
[This message has been edited by e57 (edited 06-01-2005).]
Mark Heller "Well - I oughta....." -Jackie Gleason