Aprilaire 8870 Power

magrann

Member
I am hoping someone can help me out here. I just got an Aprilaire 8870 tsat along with the 8811 protocol adapter. I will be trying to hook it all up this weekend to an Elk M1g. I don't see how to supply power to the 8870 since I am not using the distribution panel. Unless, I can just use the 24 VAC from the furnace or should I be drawing power from the Elk or do I need a seperate transformer. Sorry, I am a bit confused.

Mike
 

hult

Active Member
I am hoping someone can help me out here. I just got an Aprilaire 8870 tsat along with the 8811 protocol adapter. I will be trying to hook it all up this weekend to an Elk M1g. I don't see how to supply power to the 8870 since I am not using the distribution panel. Unless, I can just use the 24 VAC from the furnace or should I be drawing power from the Elk or do I need a seperate transformer. Sorry, I am a bit confused.

Mike

If you have a conventional furnace, you can use the 24VAC from ihe HVAC transformer to power the 8870. Just parallel off the terminals of the HVAC transformer to the 8870. The distribution panel is entirely passive and is not needed, but is handy for trouble-shooting systems with multiple thermostats. This is described in detail in the 8870 manual and pertains to most all conventional arrangements ( Single satge furnace w/ AC; Two stage furnace w/ two-stage AC, etc.) . Exceptions include if you have a boiler with air handler and AC (which is the case with one of our HVAC units ) or are including older Enerzone/Statnet thermostats in the system (They need to have a separate transformer).

The 8811 protocol adapter runs off its own AC transformer and internally creates multiple voltages. You also need to connect it.

HTH ... Marc
 

pgray007

Active Member
I am hooking up two 8870's... should I connect one to each RS-485 terminal on the 8811 protocal adapter or wire them in some other way? The documentation is a bit sparse on how to hook up when not using the distribution panel.
 

sharby

Member
I am hooking up two 8870's... should I connect one to each RS-485 terminal on the 8811 protocal adapter or wire them in some other way? The documentation is a bit sparse on how to hook up when not using the distribution panel.


My recommendation is to power the 8870 with it's own 24VAC power supply. My furnace is hooked up so that if the furnance temperature is too low, the circulator circuit boards shuts down until the furnace heats up to minimum circulating temperature.

-=*Sharby*=-
 

pgray007

Active Member
I am hooking up two 8870's... should I connect one to each RS-485 terminal on the 8811 protocal adapter or wire them in some other way? The documentation is a bit sparse on how to hook up when not using the distribution panel.


My recommendation is to power the 8870 with it's own 24VAC power supply. My furnace is hooked up so that if the furnance temperature is too low, the circulator circuit boards shuts down until the furnace heats up to minimum circulating temperature.

-=*Sharby*=-

I'm OK on the 24VAC, the furnace always supplies voltage. I'm just not sure how to connect two thermos to the 8811 protocol adapter. I've connected 2 pairs (4 wires) of cat cable at the thermos, but the 8811 documentation doesn't seem to help on connecting the therms. It seems to have two RS-485 jacks, do I connect one thermo to each or do I have to do something funky? Both termos have home run CAT5 back to my panel and are not wired in series.

Thanks!
 

Sacedog

Active Member
I am hooking up two 8870's... should I connect one to each RS-485 terminal on the 8811 protocal adapter or wire them in some other way? The documentation is a bit sparse on how to hook up when not using the distribution panel.


My recommendation is to power the 8870 with it's own 24VAC power supply. My furnace is hooked up so that if the furnance temperature is too low, the circulator circuit boards shuts down until the furnace heats up to minimum circulating temperature.

-=*Sharby*=-

I'm OK on the 24VAC, the furnace always supplies voltage. I'm just not sure how to connect two thermos to the 8811 protocol adapter. I've connected 2 pairs (4 wires) of cat cable at the thermos, but the 8811 documentation doesn't seem to help on connecting the therms. It seems to have two RS-485 jacks, do I connect one thermo to each or do I have to do something funky? Both termos have home run CAT5 back to my panel and are not wired in series.

Thanks!

You should be able to just crimp the wires together at the adapter, and hook them up to a single rs-485 port. Each stat has their own address, so they can all be hooked up to the same port.
 

hult

Active Member
I am hooking up two 8870's... should I connect one to each RS-485 terminal on the 8811 protocal adapter or wire them in some other way? The documentation is a bit sparse on how to hook up when not using the distribution panel.


My recommendation is to power the 8870 with it's own 24VAC power supply. My furnace is hooked up so that if the furnance temperature is too low, the circulator circuit boards shuts down until the furnace heats up to minimum circulating temperature.

-=*Sharby*=-

I'm OK on the 24VAC, the furnace always supplies voltage. I'm just not sure how to connect two thermos to the 8811 protocol adapter. I've connected 2 pairs (4 wires) of cat cable at the thermos, but the 8811 documentation doesn't seem to help on connecting the therms. It seems to have two RS-485 jacks, do I connect one thermo to each or do I have to do something funky? Both termos have home run CAT5 back to my panel and are not wired in series.

Thanks!

You should be able to just crimp the wires together at the adapter, and hook them up to a single rs-485 port. Each stat has their own address, so they can all be hooked up to the same port.

Using a separate RS-485 output for each 8870 has the advantage of isolating electrical (RS-485 and T-stat) faults. The 8811 is as complicated (and expensive) as it is in order to provide this feature. No good reason I know of not to make use of it. IIRC, at least the two RJ-11 have separate drivers.

.. Marc
 

Sacedog

Active Member
Using a separate RS-485 output for each 8870 has the advantage of isolating electrical (RS-485 and T-stat) faults. The 8811 is as complicated (and expensive) as it is in order to provide this feature. No good reason I know of not to make use of it. IIRC, at least the two RJ-11 have separate drivers.

.. Marc

For up to 3 thermostats, yep. The 8811 supports up to 32 thermostats, however, so if you ever had more than three, you would need to connect multiple thermostats to the same port. If you wanted to get the same troubleshooting capabilities with more than 3 stats, you would install a distribution panel.
 

pgray007

Active Member
Using a separate RS-485 output for each 8870 has the advantage of isolating electrical (RS-485 and T-stat) faults. The 8811 is as complicated (and expensive) as it is in order to provide this feature. No good reason I know of not to make use of it. IIRC, at least the two RJ-11 have separate drivers.

.. Marc

For up to 3 thermostats, yep. The 8811 supports up to 32 thermostats, however, so if you ever had more than three, you would need to connect multiple thermostats to the same port. If you wanted to get the same troubleshooting capabilities with more than 3 stats, you would install a distribution panel.

I'm still stuck on the thermos. I've connected them a couple of different ways and will get the "mating computers" logo after restarting a thermo, but after a few minutes it gets an X over it and the Elk has yet to talk to the thermo.

Here's my setup:

At each of the two 8870's I have a piece of Cat five connected as such:

B- = blue/white
B+ = blue
A- = orange/white
A+ = orange

These terminate back to a 6-connector RJ11, connected as such (Pin references are looking at the gold connectors, with the wire coming out of the bottom of the RJ11 and numbered from left to right. I.e. Pin 1 is the leftmost pin if you are looking at the connectors and holding the cable in your fist as it drops to the floor)

1 = Not connected
2 = Blue/white
3 = Orange
4 = Orange/white
5 = Blue
6 = Not connected

I have one termo terminated to each RJ6 and connected to both the RS485 jacks on the 8811. Googling suggests opening the 8811 and moving a jumper, and connecting directly to the "flying leads" (aka the four wires on the 8811). What is the right approach?

If I had know this would be so confusing I would have just bought that 88whatever termination block piece! :)

Thanks for any help!
 

pgray007

Active Member
I have one termo terminated to each RJ6 and connected to both the RS485 jacks on the 8811. Googling suggests opening the 8811 and moving a jumper, and connecting directly to the "flying leads" (aka the four wires on the 8811). What is the right approach?

Tried the "flying leads" as per the manual (looks like this):

8811 / CAT5
Blu/wht to Blu/wht
Org/wht to Blu
Red/Wht to Org/Wht
Blk/wht to Org

I just crimped the two thermos and 8811 connectors together and... NOTHING. Now I don't even get the mating computer icon on the thermos. Anyone have any ideas or should I just get the 8818 and hope for better luck? I have no idea if this is an 8870, 8811 or Elk issue.
 

magrann

Member
Just a stupid question but did you set the addresses on the thermos to 1 & 2 and then enrolled them in the elk. And are you using one m1xsp or 2? I will check your wiring and see if I can remeber what I did. I only had one thermo to deal with but shouldn't be all that different.
 

magrann

Member
Your wiring seems correct. Is your system operating manually? I will check again when I get home.

BLU/WHT to (CAT5)BLU/WHT to (8870)B- terminal
ORG/WHT to (CAT5)BLU to (8870)B+ terminal
RED/WHT to (CAT5)ORG/WHT to (8870)A- terminal
BLK/WHT to (CAT5)ORG to (8870)A+ terminal

I found this on another board but I don't think that I had to do this.

Before you connect the 8811 to the 8870 you need to remove the terminating resistor jumpers at location JP9. Remove the 4 screws from the 8811 and remove the cover. Locate JP9 and move the shunts so that are only on one side of the pins, not shorting out the pins. Replace the cover and screws.
 

hult

Active Member
Using a separate RS-485 output for each 8870 has the advantage of isolating electrical (RS-485 and T-stat) faults. The 8811 is as complicated (and expensive) as it is in order to provide this feature. No good reason I know of not to make use of it. IIRC, at least the two RJ-11 have separate drivers.

.. Marc

For up to 3 thermostats, yep. The 8811 supports up to 32 thermostats, however, so if you ever had more than three, you would need to connect multiple thermostats to the same port. If you wanted to get the same troubleshooting capabilities with more than 3 stats, you would install a distribution panel.

I'm still stuck on the thermos. I've connected them a couple of different ways and will get the "mating computers" logo after restarting a thermo, but after a few minutes it gets an X over it and the Elk has yet to talk to the thermo.

Here's my setup:

At each of the two 8870's I have a piece of Cat five connected as such:

B- = blue/white
B+ = blue
A- = orange/white
A+ = orange

These terminate back to a 6-connector RJ11, connected as such (Pin references are looking at the gold connectors, with the wire coming out of the bottom of the RJ11 and numbered from left to right. I.e. Pin 1 is the leftmost pin if you are looking at the connectors and holding the cable in your fist as it drops to the floor)

1 = Not connected
2 = Blue/white
3 = Orange
4 = Orange/white
5 = Blue
6 = Not connected

I have one termo terminated to each RJ6 and connected to both the RS485 jacks on the 8811. Googling suggests opening the 8811 and moving a jumper, and connecting directly to the "flying leads" (aka the four wires on the 8811). What is the right approach?

If I had know this would be so confusing I would have just bought that 88whatever termination block piece! :)

Thanks for any help!

Did you set the thermostats to unique addresses? See page 7,8 and 10 of the Operating Instructions (press 'Mode + Enter' simultaneously ; scroll to Communications Setup).

The "88whatever termination block piece" lets you deal with one thermostat at time, which is the same as you can do by installing them one at a tiime since you only have two ;-)

Marc
 

pgray007

Active Member
I have indeed set the thermos to 1 and 2 (out of 64, left the default), and set them up in the Elk M1G. The thermos appear in the automation menu with "Not Enabled" when I try to query the temperature.

Any other ideas? I've rechecked the wiring and Elk settings a few times but will do it all over again tomorrow unless something leaps out at one of the wise souls here.
 
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