Approxiimate Compressor Amp Draw, Old Sears Packaged Unit (cooling Only) - HVAC - Page 2 - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 05-10-2013, 07:28 PM   #16
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 10,099
Rewards Points: 836
Default

Approxiimate compressor amp draw, old Sears packaged unit (cooling only)


It does make a difference as the newer higher SEER units will run a bit different pressures then a similar lower SEER unit and the scroll compressors run different than the older recips. Understanding how a TX valve really works and how it modulates the Freon pressures/flow is also important. (Google thermostatic expansion valve for more info and Sporlan etc may have it also)There are no more rules of thumb as to what the pressures and readings should be so how does a new guy know what is normal. I tell my apprentices to record readings etc from properly functioning newer units that are fully charged so they know what is "normal" and have a reference point. If you don't have those readings at different outdoor temps/loads then you will never learn. The charging chart on all new ACs is designed with optimum large sized ducts and proper air flow but as well all know that rarely happens so those charts are a reference point only. As compressors get older they can lose capacity so those charts are not always to be used verbatim.

Advertisement

__________________
"Cut it twice and it is still too short".
yuri is online now   Reply With Quote
Old 05-11-2013, 09:21 PM   #17
Member
 
Join Date: Dec 2008
Location: Las Vegas, NV
Posts: 490
Rewards Points: 340
Default

Approxiimate compressor amp draw, old Sears packaged unit (cooling only)


Quote:
Originally Posted by justplumducky View Post
Only thing I could get from data sticker is Model Number RN _ _ _ 30, then a space followed by 807819331. Nothing on serial number. Here's the only pic Google could find that matches the cabinet style:
Attachment 70639
Tonnage and other info on data sticker not legible, but's it's on a 14' x 70' mobile home, which is maybe a 3 ton unit?

What I measured was 18 amps on both 240v legs feeding comp. I didn't know that a compressor would start up with a 40 uF run cap (single, not a dual run cap) that measured only 10 uF. Is 18A possibly a high amp draw because of the bad run cap? Blower wheel was loaded with gunk on its blades, and it's run cap was only 2.5 uF (5.0 uF new) - it wouldn't start. Forgot about giving the wheel a spin to see if it would start. It wasn't locked up however. The 18A draw was measured without blower running.

Condenser fan was running, but air wasn't coming out/up vertically (at all) from fan - was coming out mostly horizontally from around the perimeter of the opening. Forgot to amp check fan motor and check for a run cap.

There was a slight overheat spot on the disconnect box's pullout T-handle and it's corresponding spot on the T-handle's receptacle in the disconnect box. Compressor terminal connections ( posts and quick disconnects on wire-ends) were clean. Didn't see any overheat spots anywhere else in wiring or on components. Contactor points were decent- not overheated.

Fuses in disconnect box were new - maybe one of the old ones caused a problem.?
Around here we call that unit the "canned ham" model because of its shape. That is a reverse flow unit and I hear ICP finally discontinued it recently.

I have an old 1978 sears catalog with those things listed in it.
sammy37 is offline   Reply With Quote
Old 05-12-2013, 12:23 AM   #18
Member
 
Join Date: Aug 2009
Location: Southwest Ohio
Posts: 506
Rewards Points: 402
Default

Approxiimate compressor amp draw, old Sears packaged unit (cooling only)


Quote:
Around here we call that unit the "canned ham" model because of its shape. That is a reverse flow unit and I hear ICP finally discontinued it recently.

I have an old 1978 sears catalog with those things listed in it.
Sammy~ , before I found that pic I attached, I kept trying to figure out how to describe that unit and what seemed so familiar about it - Now I know!

Please tell this newbie what you mean by reverse flow. I googled for it, but came up with something that included heat exchangers, 4-way valves and some other stuff that was pretty much greek to me. Maybe you're talking about a different version of the one in the pic I posted?
justplumducky is offline   Reply With Quote
Old 05-12-2013, 11:23 AM   #19
Member
 
Join Date: Dec 2008
Location: Las Vegas, NV
Posts: 490
Rewards Points: 340
Default

Approxiimate compressor amp draw, old Sears packaged unit (cooling only)


Quote:
Originally Posted by justplumducky View Post
Sammy~ , before I found that pic I attached, I kept trying to figure out how to describe that unit and what seemed so familiar about it - Now I know!

Please tell this newbie what you mean by reverse flow. I googled for it, but came up with something that included heat exchangers, 4-way valves and some other stuff that was pretty much greek to me. Maybe you're talking about a different version of the one in the pic I posted?
Reverse flow means the return and supply air are backwards. If you ever go to replace that unit, someone could try to find that model but like I said, I'm pretty sure they discontinued it. They also made that model in a heat pump.

Around here, when we change a reverse flow unit out, we use what is called a double changeover box. A double changeover box flip flops the air around to make the duct connections match the input/output air flow of the new unit.

The best thing to do if possible, is to switch the return and supply ducts around in the attic, crawlspace, or whatever setup you have, to make the airflow match up properly to the new unit, without the need for the changeover box.
sammy37 is offline   Reply With Quote
Old 05-13-2013, 09:14 AM   #20
Member
 
Join Date: Aug 2009
Location: Southwest Ohio
Posts: 506
Rewards Points: 402
Default

Approxiimate compressor amp draw, old Sears packaged unit (cooling only)


Cool beans, thank you much Sammy~

Advertisement

justplumducky is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Can't get unit to turn on need electrical help please-wiring diagram included igotshocked Electrical 33 01-30-2014 06:13 AM
Heating and Cooling unit pauls HVAC 3 12-09-2008 09:49 AM
Furnace w Cooling unit wont turn off Klatimer HVAC 2 09-19-2008 09:35 PM
unit is trying to heat in cooling mode... gotdirtygrout HVAC 1 07-11-2008 11:00 PM
AC Unit Continuously Runs - yet it is cooling reefland HVAC 4 06-17-2007 08:04 PM




Top of Page | View New Posts