madmartian Posted January 18, 2016 Posted January 18, 2016 I have a 2000 watt 240v wall heater (TPI/Markel 4400 series). I would like to add an in-wall controller so I can use a thermostat with my ISY to turn the wall heater on and off. I have seen several options, such as: IN-LINELINC RELAY - INSTEON 2475SDB REMOTE CONTROL IN-LINE ON/OFF SWITCH (DUAL-BAND) INSTEON 2443-222 MICRO ON/OFF MODULE 220V / 240V 30 AMP INSTEON 2477SA1 LOAD CONTROLLER NORMALLY OPEN RELAY (DUAL-BAND) Some of these talk about different types of loads and some don't. Some talk about 277v (not 240) which I had never heard of. I am not clear which is best for my application. Or is there a z-wave module that would be better?
stusviews Posted January 18, 2016 Posted January 18, 2016 The NEC does not permit interrupting only one leg of a 220/240 volt device, so the devices from the first two links are out of compliance. The third link is a valid option, but several users have posted reliability concerns. The Elk relay. albeit bulky, has had good reviews. Edit: 277VAC is a standard voltage between any two phases for a 3-phase electric supply.
mwester Posted January 18, 2016 Posted January 18, 2016 The best option, IMO, is to build your own. Use a 2-pole contactor relay, usually intended for air conditioner use, with a 110/120 VAC coil. You can find these on eBay - I picked up a Packard unit, rated at 30 Amp (overkill), to use with my second well pump, for a few bucks. Wire the coil so that it is energized by a micro on/off unit if you don't need local control, otherwise use a switchlinc on/off to control the relay. The relay fits nicely in a PVC electrical box with the micro on/off, or you used a switchlinc it's probably easier to put it in a small box of its own, and wire it to the box containing the relay. (if a device can switch 277 VAC, it'll also handle 240 VAC safely -- just make sure that if the device says 277VAC it does not ALSO say that it requires 3-phase power; that a whole 'nother deal)
stusviews Posted January 18, 2016 Posted January 18, 2016 Only 3-phase devices require 3-phase power. Most commercial buildings and large apartment buildings have a 3-phase electric supply. A 110/120 volt device is powered between any phase phase and neutral, 220/240 volt devices are supplied by any two phases. Elevators usually use 3-phase power because swapping any two phases reverses the direction.
larryllix Posted January 18, 2016 Posted January 18, 2016 The second unit you listed is a 240v module that doesn't require the neutral connection and has a heavy duty contact designed for water heater usage. https://www.aartech.ca/related/2477SA1.pdf The 120v and 277v units are designed to be used with a neutral and you won't be using one. 277v is the single phase voltage of only one phase to neutral in a 277/440v three phase 4 wire system.
madmartian Posted January 18, 2016 Author Posted January 18, 2016 To clarify, the wall heater has no external switch - the 240 wires are connected directly from the panel to the heater, which has it's own internal switch and thermostat. There is no 120v source for switching, so the Elk relay won't work. There IS a neutral wire, so I believe all 3 options can work, though I am unclear which can handle the 2000 watts as ratings appear to depend on the type of load. My house is 2-phase, so anything requiring 3 phase wiring is out.
larryllix Posted January 18, 2016 Posted January 18, 2016 The first module, In-LineLinc Relay - Insteon 2475SDB Remote Control In-Line On/Off Switch (Dual-Band, is not rated high enough for the 2000 Watt heat load. The Insteon 2443-222 Micro On/Off Module appears to be rated for it and is usable for 240 vac with a self-configuring 50/60 Hz for European 240vac, (may or may not be grounded return) usage. It should be fine if built inside the heater unit, barring heat exposure burning it out. The whole thing would never be passed on an inspection as you would be modifying the accepted and approval configuration. Between you and me, I would have no problem installing this INSIDE the heater metal case, with a proper heat shield, and ventilation to keep it cool enough, as long as there is an existing built in thermostat that can be used for a high limit should the control / comm / ISY program / programmer / whatever, fail. There should be an existing single pole thermostat and/or high-limit built into the heater unit, that must stay in operation, in electrical series, otherwise I would not do the modification, which could endanger you, your family, and neighbours, with the risk of fire or smoke inhalation. Be warned. The third option would likely be better but you would be switching only one leg of the dual leg circuit outside of the device and as Stu posted, this would be outside of your safety code. There is always a reason for the safety code rules, apparent to us or not. I know 240v thermostats were mostly done this way, but things may have changed over the years. Stu would know more about this than me.
stusviews Posted January 18, 2016 Posted January 18, 2016 If you have a neutral wire, then you do have 110/120VAC available. That's the voltage between either leg of the 220/240V source and the neutral wire.
madmartian Posted January 18, 2016 Author Posted January 18, 2016 ...There should be an existing single pole thermostat and/or high-limit built into the heater unit, that must stay in operation, in electrical series, otherwise I would not do the modification, which could endanger you, your family, and neighbours, with the risk of fire or smoke inhalation. Be warned... Indeed there is an internal thermostat and limiter, neither of which can be bypassed. The section with the wires is isolated from the heater, so if I can fit the unit in there is should be fine. The 3rd option would most definitely not fit in that space. The idea is to work much the same way a Cadet thermostat works, except in this case the switching will be done remotely instead of via an external direct-wired thermostat. I have a second wall heater with a an external Cadet direct-wired thermostat that is too close to the heater to be useful. I will likely be replacing that thermostat setup as well, but that one is 4000 watts and none of the above units can handle that. One project at a time. The easier one first.
stusviews Posted January 18, 2016 Posted January 18, 2016 You can also use an Aube relay with any standard thermostat including Insteon or Z-Wave or Nest or ... .
larryllix Posted January 18, 2016 Posted January 18, 2016 You can also use an Aube relay with any standard thermostat including Insteon or Z-Wave or Nest or ... . That looks like a nice way to do it, adding an Insteon thermostat to the 24vac wiring facilities provided. They should it being added to a baseboard type strip heater. The manual schematic shows it connected L1-L2, but the wiring diagram shows it connected to a neutral. Probably just a slip of the copying pen, as it is rated for 240vac in Canada, well Quebec, anyway.
stusviews Posted January 18, 2016 Posted January 18, 2016 I don't see a neutral in the wiring diagram. Although the primary use is for a baseboard heater, the Aube relay can be connected to any 220/240VAC device that someone wants to control using a thermostat.
madmartian Posted January 18, 2016 Author Posted January 18, 2016 Just to be sure, I opened up both wall heaters to check on the wiring. Indeed there is one set of wires coming in - Black, White, Ground (no red) and one set going out (same) to the other wall heater. There is another set on the small heater to allow control via a wall timer (similar on the big heater with a Cadet thermostat). What I found interesting is that whoever installed the wall timer put it in series with the neutral instead of the hot. No electrician would do that, so must be the previous owner's fancy footwork (dealt with quite a bit of that, including miswired 3-way switches and a "switch to nothing" that I still haven't figured out). So I need to rewire that heater anyway. I installed the thermostat on the big heater, thus it is installed correctly. I think for now I'm going to go with the micro on/off. The Aube looks interesting but requires a wired thermostat, which is what I am trying to avoid. Thanks everyone for your help.
stusviews Posted January 18, 2016 Posted January 18, 2016 If the heater is a 220.240 volt heater, then the white wire is not a neutral wire. A 2-wire Romex cable is available only with one black and one white wire plus ground, so white has to be used for one leg of the split, single-phase electric supply. The white wire should be, but isn't always, marked as such usually with colored tape. AFAIK, the Micro Module requires a neutral wire.
Cormacs Posted January 19, 2016 Posted January 19, 2016 If the heater is a 220.240 volt heater, then the white wire is not a neutral wire. A 2-wire Romex cable is available only with one black and one white wire plus ground, so white has to be used for one leg of the split, single-phase electric supply. The white wire should be, but isn't always, marked as such usually with colored tape. AFAIK, the Micro Module requires a neutral wire. Unless your in Canada. They should be using red insulated romex. Which contains red and black, no white. Sent from my iPhone using Tapatalk
larryllix Posted January 19, 2016 Posted January 19, 2016 Unless your in Canada. They should be using red insulated romex. Which contains red and black, no white. Sent from my iPhone using Tapatalk ...And tape marking doesn't cut it, unless you can warp it from one end to the other end continuously and then put the jacket back on. But this is a recent (last thirty years) advance in Canada that probably hasn't caught on in the USofA.
larryllix Posted January 19, 2016 Posted January 19, 2016 I don't see a neutral in the wiring diagram. Although the primary use is for a baseboard heater, the Aube relay can be connected to any 220/240VAC device that someone wants to control using a thermostat. It's actually the pictorial of the schematic on the front cover of the Aube in the manual, section 5. The photo of it shows L1-L2 and disagrees with the manual pictorial..
stusviews Posted January 19, 2016 Posted January 19, 2016 Unless your in Canada. They should be using red insulated romex. Which contains red and black, no white. Sent from my iPhone using Tapatalk Australia and New Zealand have red and black Romex w/o white. I've never seen that in the US. Is that standard in Canada?
Cormacs Posted January 19, 2016 Posted January 19, 2016 Yes only for 12/2. They have a special red sheathed romex that has no white. Otherwise standard procedure is to run #/3 for 220/240 so that you don't use white on a live run, white would just be unused. Canadian code your not allowed to run a live load over white. Sent from my iPhone using Tapatalk
stusviews Posted January 19, 2016 Posted January 19, 2016 ...And tape marking doesn't cut it, unless you can warp it from one end to the other end continuously and then put the jacket back on. But this is a recent (last thirty years) advance in Canada that probably hasn't caught on in the USofA. The NEC requires only that the wire be marked at each end. It can be tape (most common) or paint or anything else as long as the marker differentiates the wire from neutral. Any color can be used except green (ground only) or gray (an alternate to white, usually used when there is more than one neutral wire).
larryllix Posted January 19, 2016 Posted January 19, 2016 Australia and New Zealand have red and black Romex w/o white. I've never seen that in the US. Is that standard in Canada? Yes. I know the red jacket is required but I wasn't sure about the red and black conductors but I think that is the only way to get it. Now we have Orange jackets and blue, all becoming code slowly. Yuk! Home Depot looks like a circus in the wire section.
Cormacs Posted January 19, 2016 Posted January 19, 2016 The NEC requires only that the wire be marked at each end. It can be tape (most common) or paint or anything else as long as the marker differentiates the wire from neutral. Any color can be used except green (ground only) or gray (an alternate to white, usually used when there is more than one neutral wire). Canadian code states it must be permanent marking, electrical tape isn't considered permanent. From what ive heard they changed it that marking the ends doesn't suffice as someone may mistaking splice in half way and confuse it for 110. Sent from my iPhone using Tapatalk
larryllix Posted January 19, 2016 Posted January 19, 2016 Canadian code states it must be permanent marking, electrical tape isn't considered permanent. From what ive heard they changed it that marking the ends doesn't suffice as someone may mistaking splice in half way and confuse it for 110. Sent from my iPhone using Tapatalk I think the NEC requires a red with white and blue conductors.
stusviews Posted January 19, 2016 Posted January 19, 2016 ...And tape marking doesn't cut it, unless you can warp it from one end to the other end continuously and then put the jacket back on. But this is a recent (last thirty years) advance in Canada that probably hasn't caught on in the USofA. How do you put the jacket back on Romex?
Cormacs Posted January 19, 2016 Posted January 19, 2016 From what I read it was adopted in 2011, a white conductor can no long be used to carry ungrounded potential. Anything already using it can be marked at the ends but new installations it's considered unacceptable. Sent from my iPhone using Tapatalk
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