Insteon Wireless Thermostat (2441ZTH)

[BigEfromDaBx]

I have a portable AC in my garage and want to know if I can power up and down my portable ac once the wireless thermostat reaches a certain temperature. 

 

 

 

Below are the products I wish to use.

 

http://www.smarthome.com/insteon-2441zth-wireless-thermostat.html

http://www.smarthome.com/insteon-2635-222-on-off-module.html

[Teken]

Your first important task is to confirm how the AC unit behaves once power is applied vs removed. Failure to validate proper operations can result in a failed project vs damaged AC unit.

[smokegrub]

I have researched this application several times and I have found no way it can be done, at least not with my unit. Any time the power to the unit is interrupted it must be restored manually. In my situation by pressing a button on the unit. I have a propane furnace that is started electronically and it requires the same. 

[apostolakisl]

The simplest way to do that would be to put a switch on the power supply.  But as mentioned, restoring power to the unit might not turn it on if it has any sort of "smart" control.  It might come on to a standby mode requiring you to push a button on it.

[BigEfromDaBx]

Your first important task is to confirm how the AC unit behaves once power is applied vs removed. Failure to validate proper operations can result in a failed project vs damaged AC unit.

 

The AC advertises to keep its setting when the power is cut on and off.

When it loses power and its restored it goes right back to normal

[Teken]

The AC advertises to keep its setting when the power is cut on and off.

 

When it loses power and its restored it goes right back to normal

Your going to want to confirm that happens in real world use vs paper specs.

 

If the hands on test validate what the paper specs say. Your next step is to install the various Insteon hardware and confirm proper operations. Key area is communications and the network has no issue turning the AC off.

 

Be mindful the AC unit falls within the Insteon power handling capability. If so great - the next step is to move forward with integrating the TSTAT and rinse & repeat the validation process that all systems operate as expected.

 

You will need to build in some safety programs in the ISY Series Controller for watch dog timers for just in case there are power blips.

 

Short cycling the breaker and TSTAT while watching how the AC reacts is imperative.

[BigEfromDaBx]

Your going to want to confirm that happens in real world use vs paper specs.

 

If the hands on test validate what the paper specs say. Your next step is to install the various Insteon hardware and confirm proper operations. Key area is communications and the network has no issue turning the AC off.

 

Be mindful the AC unit falls within the Insteon power handling capability. If so great - the next step is to move forward with integrating the TSTAT and rinse & repeat the validation process that all systems operate as expected.

 

You will need to build in some safety programs in the ISY Series Controller for watch dog timers for just in case there are power blips.

 

Short cycling the breaker and TSTAT while watching how the AC reacts is imperative.

Ok.  So your saying I can do that with the wireless thermostat I have?

[Teken]

Ok.  So your saying I can do that with the wireless thermostat I have?

 

Yes, assuming your Insteon network (RF) mesh is strong and reliable. Key things for a successful Insteon home automation is to ensure the following:

 

- Proper coupling / bridging of the split single phase electrical system. Confirm via the 4 tap beacon test outlined in any products full users manual.

 

- Identify any noise makers / signal suckers and filter, remove, replace.

- Verify the AC units power handling falls within the On-Off relay modules specs.

- Confirm the On-Off relay module can reliably turn off the AC unit when its fully operational.  

[stusviews]

- Confirm the On-Off relay module can reliably turn off the AC unit when its fully operational.  

 

Off is easy. The real test is turning the unit on.

[Brian H]

Insure that you don't do a short cycle. Where the time period between the Off and the next On is short.

Could be damaged by a short cycle.

 

Almost all of the permanently installed HVAC units have a 5 minute time out between calling for a Cooling cycle.

I know my portable room air conditioner use the have restarting issues if the power cycled Off and back On in a short time period.

[apostolakisl]

Yes, if you turn off, then back on too soon, the downstream refrigerant will still be under high pressure.  So if the compressor tries to start against that load, it won't spin, electricity will flow, and the coils will overheat and fry.

 

If you wait, after a few minutes, the pressure bleeds down until the suction side and the compressed side become equal.  Then the compressor can start without undue loading.

 

I'm assuming an Insteon thermostat has short-cycle protection built-in to its programming?

[Teken]

As I noted this is why the short cycle test must be performed to validate every system operates as expected when required. The reality is every home will experience a short cycle at some point when there are issues with the POCO or during extreme weather conditions. Best to know, test, and validate what will happen in a controlled manner.

 

Also note this may not be plainly obvious but if the On-Off relay is off this is the last known state and this position should remain in place. Short cycling the breaker will not turn the Insteon module back on unless there is something wrong with the device.

 

This is really a poor mans safety switch and thus is why the ISY must be programmed also to have extra safeties in place to guard against other conditions or out of band use cases.

 

Those reading my reply are getting the benefit of someone who has years of testing and having everything going wrong in a similar use case.

 

It should be clear by now short cycling is not recommended in normal circumstances but in this case your testing and proving out every condition and element operates as expected.

 

 

=========================

 

The highest calling in life is to serve ones country faithfully - Teach others what can be. Do what is right and not what is popular.

[BigEfromDaBx]

Yes, if you turn off, then back on too soon, the downstream refrigerant will still be under high pressure.  So if the compressor tries to start against that load, it won't spin, electricity will flow, and the coils will overheat and fry.

 

If you wait, after a few minutes, the pressure bleeds down until the suction side and the compressed side become equal.  Then the compressor can start without undue loading.

 

I'm assuming an Insteon thermostat has short-cycle protection built-in to its programming?

 

If you turn it on and off the compressor wont start right away.

[larryllix]

When the compressor us shut off the refrigerant pressure equalising can turn tge compressor motor backward. If yoy turn on the compressor while the motor is turning backward, most motors will start in reverse.

 

Now you can destroy your whole system.

 

The time delay is needed to protect your system.

 

I did this once, due my stat and compressor on different curcuits, and hopefully my compressor wasnt damaged. Luckily I was outside, heard the awful noise of a compressor running backwards, and responded quickly to the breaker panel, just dropping the compressor circuit.

 

http://hvac-talk.com/vbb/showthread.php?919272-single-phase-copeland-scroll-running-backwards

 

Sent from a tiny keyboard. Response may be brief.

[apostolakisl]

If you turn it on and off the compressor wont start right away.

If you do it from the on/off switch on the unit I'm sure it won't.  But you should also make sure that the same is true if you go from on to off to on again by pulling the power.