Upgrading old 700 for new 700 humidifier


  #1  
Old 01-20-19, 08:27 AM
M
Member
Thread Starter
Join Date: Jan 2019
Location: Canada
Posts: 6
Upvotes: 0
Received 0 Upvotes on 0 Posts
Upgrading old 700 for new 700 humidifier

I could really use very similar assistance as well : )

I am upgrading in in-place tan 700 with newer gray 700...in a Carrier Infinity that already manages all the humidity control so there is no attached controller other than the Infinity one that manages.

I removed the PLUG style power cord from new one and adopted the old power cord already wired to furnace (just attached spades and ground to new humidifier)

seems I have no water nor fan when humidity should be called for.....this TRANSFORMER seems to loom large but not sure how to incorporate...OR...if I might already have caused any physical damage wiring as permearlier version that had on board transformer.

getting a little confused...can you guide me rest of the way ?

thanks in advance...M
 
  #2  
Old 01-20-19, 02:26 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 64,816
Received 3,922 Upvotes on 3,518 Posts
Welcome to the forums.

I moved you to your own thread to eliminate cross confusion.

The power cord will still need to be plugged in with the new unit. It may have been switched with the blower AC power. That will no longer work for the new unit. The new unit requires always live power.

The new unit needs to be connected directly to the furnace control board. If you can post a picture of it or post the part number.... I can help you further.

How-to-insert-pictures
 
  #3  
Old 01-21-19, 04:46 AM
M
Member
Thread Starter
Join Date: Jan 2019
Location: Canada
Posts: 6
Upvotes: 0
Received 0 Upvotes on 0 Posts
Good morning...thanks for getting back to me so quickly. I will get the additional details for you and try to illustrate present connections too.

A couple of questions meanwhile for clarification.

Why would the new 700 necessarily require constant power and need to be PLUGGED in.....if I am not using any humidity controller attached to it ? (The Carrier has the outside temp sensor attached to it and all humidity related settings done thru the Infinity thermostat).....can it not still be switched ?

When you say new “unit” needs to be connected to furnace control board, is it the separate TRANSFORMER you are referring to ?

thanks M
 
  #4  
Old 01-21-19, 10:12 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 64,816
Received 3,922 Upvotes on 3,518 Posts
The 700 needs AC power to run the internal fan.
 
  #5  
Old 01-21-19, 11:07 AM
M
Member
Thread Starter
Join Date: Jan 2019
Location: Canada
Posts: 6
Upvotes: 0
Received 0 Upvotes on 0 Posts
Opened up panels for pics...I think it may already have constant AC power even though it is hardwired (I’ll try to upload pics I have taken) but the power cord I adopted from the old one is spliced into the AC power coming into the furnace...and the other end I have connected the spades and ground to new 700 and fan.

Then there is wire from furnace HUM to the sensing relay...and the other wire to sensing relay is coming from furnace 24V COM....then the other wires from sensing relay go to the brown wires on the 700.

does that setup sound like only the standalone transformer needs to be incorporated or changes could still be more extensive ?

thanks again...M
 
  #6  
Old 01-21-19, 11:12 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 64,816
Received 3,922 Upvotes on 3,518 Posts
Then there is wire from furnace HUM to the sensing relay...and the other wire to sensing relay is coming from furnace 24V COM....then the other wires from sensing relay go to the brown wires on the 700.
You will remove that sensing relay and send HUM and C directly to the humidifier.
When the furnace heats..... the humidifier will run.

Any humidistat here ?
 
  #7  
Old 01-21-19, 02:39 PM
M
Member
Thread Starter
Join Date: Jan 2019
Location: Canada
Posts: 6
Upvotes: 0
Received 0 Upvotes on 0 Posts
Hi Pete...

as indicated earlier, all humidstat controls are thru the Carrier furnace Infinity thermostat...I am not using humidistat or controller equipped by Aprilaire....nor did the old one.

You didn’t mention the TRANSFORMER this time around...what am I doing with that since this new version of Aprilaire does not have the built-in one ??

Are you able to comment in layman’s terms why I no longer need the sensing relay ?

Your instructions thus far are clear but I don’t feel like I have any sense of understanding anymore re diff between the setup for the old/new and WHY. For eg...pretty sure the old setup would NOT work without the sensing relay...and had the transformer. This new setup does not need the relay AND now doesn’t need the transformer included either ?!

Is that due to the various outputs on my high end Carrier ?!

Thanks.....I’m going to hold off bypassing the RELAY until I’m clear on need (if any) for the transformer...a little worried that I could BLOW a circuit board or something if I was unclear on any step of your instructions. (If you prefer to reserve any further instructions until you see some pics, I understand but just don’t think I’ll find time u til later tonight at earliest)

UPDATE.....I can see that new 700 model has a RELAY built in so that may explain why I don’t need other, but does other relay need to be removed in order for humidifier to work...or is it just redundant ? Maybe will make more sense once I hear back and or figure out what role if any transformer is going to play (thanks in advance for patience)
 

Last edited by Moolala; 01-21-19 at 03:30 PM.
  #8  
Old 01-21-19, 07:28 PM
M
Member
Thread Starter
Join Date: Jan 2019
Location: Canada
Posts: 6
Upvotes: 0
Received 0 Upvotes on 0 Posts
I’m going to remove/bypass the sensing relay that is in place as instructed (easy enough) and retest !! (after reading some more about it, I’m not convinced the Carrier ever needed it in the first place)...I’ll assume the output from it while in place is causing problems for the new built-in relay. Starting to get impression, I don’t need the transformer either (since I don’t use digital humidistat controller) but guess I will know soon enough. Fingers crossed.....it’s about 100 below outside so not keen on creating problem with the FURNACE in the process. Going to wait u til morning before attempting to be on the safe side.

Really appreciate the assistance...thanks. All the existing prescribed wiring from Aprilaire seems to go right out the window with the Carrier furnace and interface for humidification.

Have a good one !!
 
  #9  
Old 01-21-19, 08:04 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 64,816
Received 3,922 Upvotes on 3,518 Posts
Your old humidifier had a self contained transformer. All that was needed was for the two wires to be shorted together and the humidifier ran. All they've done is to take the transformer out of the new one. They both have internal relays to operate the fan.

Your HUM and C represent 24vAC. If you connected that 24v to the internal voltage of the old one..... you'd have damage. That relay isolated the furnace 24v from the humidifier 24v transformer.

You can leave that relay in place as currently wired and use the 24v transformer that comes with new humidifier.

Look at the diagram. This represents your new setup. I drew it with the new 24v transformer in place. The relay closes the circuit with the new transformer. Now.... for your old 700..... picture that transformer mounted inside the cabinet but still in the black wire. Then you'd only need to short the two control wires. Make sense ?

Name:  c700.jpg
Views: 137
Size:  43.4 KB
 
  #10  
Old 01-22-19, 05:21 AM
M
Member
Thread Starter
Join Date: Jan 2019
Location: Canada
Posts: 6
Upvotes: 0
Received 0 Upvotes on 0 Posts
Two things...

1. I removed relay in furnace last night and made the revised connections. WOOHOO.....humidifier fan and water upon restart !!!!

2. And.....YES.....after looking at your pic for extended period the light finally dawned on me that the relay merely makes the CONNECTION (black and white in your pic) it is not sending the 24V from furnace beyond the relay...so, until rewiring last night, the NEW 700 did not get 24V to close it’s connection to allow it to run (at least pretty sure that’s it haha)

More importantly...thank you so much for the generosity of your time...and the consideration given to my problem. It was huge help and my comfort level was considerable due to similar guidance I knew you had provided for others previously. Much appreciated Pete !!
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: