Lux 722E Thermostat - http://www.hvacmechanic.com/ Forums
Original message
| mgkicker
 |  "Lux 722E Thermostat"
, posted Thu 26 Oct 15:20  
Hello,
I have a question that I would really appreciate some help. I found the
perfect Thermostat in my opinion for my specific setup. LuxPro PSP722E
Programmable MultiStage Thermostat (I have a 1 stage heat pump and Electric
Emergency heat). Can I add on someone else's out door sensor to this
Thermostat? I called the company and even though the stat handles
outdoor/indoor sensor, Lux does not manufacture a sensor unit(they said
"it is in development, we had a prototype but we were not happy with it.
We should have something out by next year"). This feature is very important
to me and this is why I need to know if I could use a honeywell sensor or
wherever.
I know this post is getting kind of long, but let me just point out why I
think this stat may be the best (if it works as advertised). I had a robertshaw
non-Programmable that I just changed to a honeywell vision 7400D only to find
out that it is short cycling (sometimes compressor only on for 6 minutes Due
to a lack of "swing/differential" adjustment. Too bad because the unit looked
good!). I did my research and found the lux which does the following that
amazes me:
-1st and 2nd differential adjustment in .25F* increments.
-fan delay on heat or cool for both on and off (no more cold blasts).
-compressor locked out below a certain temperature (this is why I really need
the outdoor sensor, it gets below freezing and right now I have to manually
switch it to emergency heat).
-smart recovery locks out the emergency heat for the first 30 minutes and gives
the heat pump a chance to do its job(saves money)
The only other Thermostat that comes close to my needs is the Robertshaw 9720i,
but that is too expensive for me and I will still get cold blasts (no fan delay
for ON only for OFF). I will appreciate any help regarding the wiring of "any"
outdoor sensor to the LUX unit before I buy it. Thank you very much in advance.
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Replies:
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| Freon
| "Re(1):Lux 722E Thermostat" , posted Thu 26 Oct 16:10
An outdoor/indoor temperature sensor is usually a thermistor. If Honeywell uses a different thermistor then RobertShaw, you can see the two sensors are not interchangeable. The thermostat is designed to work with one thermistor's characteristics. Rather than hoping you'll get lucky, buy a thermostat that's paired with a thermistor. Are you sure the LuxPro PSP722E has a sensor input terminal yet? The RobertShaw you mentioned also has remote sensors that I have found very useful. Yes, it's pricy but you get what you pay for in terms of configurability, if that's what you're looking for.
As for Honeywell 7400D, did you look at the cycles per hour setting? That's Honeywell's answer to temperature differential although I personally prefer differential setting like the RS 'stat you mentioned--it's a great 'stat, IMHO.
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| | mgkicker
| "Re(2):Lux 722E Thermostat" , posted Thu 26 Oct 17:00
Thank you for the replies.
Freon,
The honeywell did not give me an option for cycles. I believe that is only available
in the next one up (touch screen), but I will double check before returning it. From
what I read in my research the LUX stat can accept 1 outdoor and 2 indoor sensors.
I do not know if there are inputs for each sensor connected. As far as the RobertShaw,
I had convinced my self it was worth it until I saw the LUX which offered more features
(more but maybe not better). The specs for the lux on the lockout feature were clear,
but on the RobertShaw it was not clear if it would do the switch from heat to Emer.
Heat and then back, I am assuming it would. RobertShaw 9720 does not have fan delay for
heat on ON (cold blasts at startup). All those features sound amazing, but you might be
right about "you get what you pay for".
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| | Freon
| "Re(3):Lux 722E Thermostat" , posted Thu 26 Oct 23:02
The one I am familiar with is the RobertShaw 9715i. It does have programable fan on timing as well as indoor and outdoor sensors.
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| acefurnacefxr
| "Re(1):Lux 722E Thermostat" , posted Thu 26 Oct 16:00
I have never installed a "LUX" stat..........but i have thrown hundreds of them in the shit can.
My spelling sucks thats why I am not a teacher.
22 years of running HVAC service calls Man I have seen it all.
I belong to a union
I also belong to a gym a campground and Triple A.
I may tell you whats wrong but its my job to fix it not yours.
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| | mgkicker
| "Re(2):Lux 722E Thermostat" , posted Fri 27 Oct 14:04:
I e-mailed LUX following a the phone conversation where I asked
about the sensor and I have not gotten a response back. So it seems that I am between a robertshaw 9720i or a more reasonable priced honeywell TH8320U. Please let me know your opinions about which one would be better, as I think they both are very similar in terms of feature and quality. I e-mail honeywell for a clarification on "cycles per hour", as it is not clear what differential is chosen (not like the robertshaw, which clearly adjusts based on what you want and not what the EPROM thinksyou need).
Also if you guys know of any other good thermostat that does 1st and 2nd stage differential, automatic change form HP to Emer. heat based on outside temp and fan delay to prevent cold blasts please let me know.
Thank you,
Max G.
[this message was edited by mgkicker on Fri 27 Oct 14:06] |
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