Replies

1. 
   JTC1 | Apr 24, 2009 03:41pm | #1

   Bump.

   Can't answer your question with any real authority, I have never done it - I would contact the manufacturer of the panel which is feeding the bedroom circuits -- Square D, Cutler-Hammer, whoever.

   >>I know they make a 2P but what do I do with the neutral? All the heaters have are two hots and a ground.<<

   Had recent similar situation, spa heater, pure 240v load, GFCI protection required: 2 hots + ground, no neutral conductor installed.

   Used a 2 pole, GCFI breaker. Connected the pigtail from the GFCI breaker to the neutral bar in sub panel, load ground wire to ground bar in sub-panel, 2 hots to breaker; neutral connection screw on breaker was left empty.

   Cutler-Hammer breaker and panel. Manufacturer sanctioned connections. Tests OK, passed electrical inspection without any comments from inspector.

   This inspection covered only the spa, it's outdoor sub-panel, and connections at the SEP. Sub-panel contained only the 240 heater line, and a shared neutral 30a 120v line which drives the pumps and displays - two, 2 pole breakers. Inspector really did look at all - sometimes I get inspections which are "inspected in name only".

   Jim   

   Never underestimate the value of a sharp pencil or good light.
1. 
   toolbear | Apr 25, 2009 03:18am | #4

   Inspector really did look at all - sometimes I get inspections which are "inspected in name only".@@@Had one at a remodel that we though was perhaps slightly intoxicated. But he was happy. "Yes, sir, and if you could initial here and here and here." He was happy and we were happy. I make sure my panel is a thing of beauty. Figure it might buy me some slack by setting the tone.The ToolBear

   "You can't save the Earth unless you are willing to make other people sacrifice." Dogbert

2. 
   BillHartmann | Apr 24, 2009 07:05pm | #2

   The AFCI requirement is on OUTLETS, which is anyplace that electrical power is connected to a load. That include the heaters.

   However, I believe that it is only needed on 120 circuits, not 240.

   If I don't get back to you in a day then let me know.

   But I only have the 2005 NEC and I believe that there was some extension of the AFCI requirements in the 2008.

   .
   William the Geezer, the sequel to Billy the Kid - Shoe
1. 
   toolbear | Apr 25, 2009 03:13am | #3

   Will a CAFCI work with only two hots, no neutral?@@@Did learn that in these upgrade jobs it's not enough to double the panel size. Went from a 6/12 maxed out Zinsco to a 12/24 Murray and had to use half heights and guadies everywhere that didn't have an AFCI.The ToolBear

   "You can't save the Earth unless you are willing to make other people sacrifice." Dogbert

1. 
   BillHartmann | Apr 25, 2009 04:06am | #5

   It should work with no neutral. But I have no personal experience with an AFCI.The AFCI uses 2 test. One is a ground fault leakage. Similar to a GFCI, except it trips at a higher current (forgot if it is 30 or 60 ma). The purpose is to detect deteriorating insulation and not personal safety. And I know that will work fine without the neutral.The other test works by measuring the signature of the noise that the arc makes and differentiate that from normal arcing such as brush on a vacuum cleaner or thermostat contacts on the heater.Don't really know of the details about how that is done. But if it is sold as a 2 pole AFCI breaker then it should work fine unless the instructions say that it is only for shared neutral circuits and not for any 240 loads..
   William the Geezer, the sequel to Billy the Kid - Shoe

1. 
   excaliber32 | Apr 25, 2009 08:29pm | #6

   An AFCI will not work without a neutral, period.

   Your heaters do not require an AFCI breaker.

1. 
   BillHartmann | Apr 25, 2009 08:44pm | #7

   "An AFCI will not work without a neutral, period."Specifically we are talking about a 2 pole (120/240) breaker feeding a 240 only load. The neutral pigtail will be connected to the neutral bus.His concern was the fact that there is no neutral connection to the 240 only load and thus nothing to hook to the load side neutral terminal on the breaker.Are you saying that a 2 pole AFCI will not work with a 240 only load?.
   William the Geezer, the sequel to Billy the Kid - Shoe

2. 
   excaliber32 | Apr 26, 2009 07:35pm | #9

   I have never seen a two pole AFCI. If I'm not mistaken, the requirements for AFCI are bedroom lighting and branch circuits, not appliances.  

   The AFCI breaker monitors current differences in the ungrounded and grounded conductor. A current spike causes the breaker to trip. I'm guessing its a eutectic alloy keeping tension off of a spring. Most 240V loads do not require a grounded conductor (neutral) unless there is a ton of electronic components. The neutral from the load connects to the AFCI, and a pig-tail to the bus. No load neutral, no functioning AFCI.

   Edited 4/26/2009 12:36 pm ET by excaliber32

3. 
   BillHartmann | Apr 26, 2009 10:15pm | #10

   "I have never seen a two pole AFCI. If I'm not mistaken, the requirements for AFCI are bedroom lighting and branch circuits, not appliances."From the 2005 NEC"210.12 Arc-Fault Circuit-Interrupter Protection
   (A) Definition: Arc-Fault Circuit Interrupter An arc-fault circuit interrupter is a
   device intended to provide protection from the effects of arc faults by recognizing
   characteristics unique to arcing and by functioning to de-energize the circuit when an arc
   fault is detected.
   (B) Dwelling Unit Bedrooms All 120-volt, single phase, 15- and 20-ampere branch
   circuits supplying outlets installed in dwelling unit bedrooms shall be protected by a
   listed arc-fault circuit interrupter, combination type installed to provide protection of the
   branch circuit."All 120v OUTLETS in a bedroom need protected. In the code an OUTLET is any place that connections are made to equipment that uses electricity.If it was 120 heater or maybe a built in coffee maker or through the wall AC that was hard wire on 120 it would still be covered.That is why smokes need to be on AFCI's which I think is a BIG MISTAKE.Now unless this was changed in the 2008 to include 240 v outlets then the heater would need one."The AFCI breaker monitors current differences in the ungrounded and grounded conductor. A current spike causes the breaker to trip. I'm guessing its a eutectic alloy keeping tension off of a spring."Not exactly. Now I am not that familar with the internal workings of an AFCI, but am somewhat knowledgable about the workings of a GFCI.The GFCI trips at 0.005 amps on a difference between net sum of the hot lead(s) and the neutral. AFCI's trip at 0.030 amps difference.Other than the trip point I don't have any reason to suspect that the AFCI works any differently.Now the AFCI also has additional features that detect certain current spikes, that are way to fast for any over current detection, of certain patterns to indicate that they come from breakdown of the connection or insulation and not an arc from a switch or vacuum cleaner brushes.The GFCI's have a transformer through which all of the load wires pass. The output signal is proportional to the net difference in the current in hot(s) and the neutral. That difference means that current is faulting to the "ground" by one means or another. And a ground path is the only way that you can get a difference in the currents.That signal is amplified and used to trigger a latching relay which breaks the circuit. Current GFCI's have some fail safe features and I don't know exactly how they are implemented but it might be that the amplifier holds in the relay and releases it if there is a current difference. Not sure of the details of how they handle that it. I do know that the self-test and Reset work much differently than on the old ones.And 2 pole GFCI's are common and they will work on any combination 120 and 240 loads. Some of the original ones did not have a neutral connection and would only work on 240 loads.I am under the understanding that 2 pole AFCI's where developed mainly for retrofit in places with multi-wire circuits had to been to bedrooms. Those are shared neutral circuits and in this application would only have 120 loads on each hot..
   William the Geezer, the sequel to Billy the Kid - Shoe

2. 
   toolbear | Apr 26, 2009 05:29am | #8

   Thanks for looking that up. I need to hit a supply house to find this one. Bit much for Homer D.The ToolBear

   "You can't save the Earth unless you are willing to make other people sacrifice." Dogbert