Carrier heat issue

I have a 02 carrier heat pump 2 ton an the Heat strips don't seem to be coming on.reguardless of E Heat or aux.
I replaced sequencer relays an it didnt change anything
What is the next thing to look at on this ,I didn't see typical sequsequencer on this..
It does go into defrost fine an kicks in as operated but no heat.
Any information is appreciated.

Will try to send pics

 

Here is a few pics
Had trouble getting pics loaded on app

 

Here are a few more but I know it's not easy to see with multiple wires.
I also replaced relays w no avail

 

Turn off power to the unit, verify that the power is off with a volt stick then isolate the heat strip and take an Ohm reading across the heat strip. A broken heat strip is often very obvious but the fuse link would need to be proven with a multimeter.

I would measure for 22 volts DC to the relay when an electric heat demand is present.
I would measure for potential voltage at the 2 high voltage connections to this heater control as well.
Zero volts would indicate a closed circuit and 240 volts AC would indicate potential voltage.
The presents of potential voltage would indicate that the control is holding you out.

 

Thanks I'll try that.
Where are the fusable links usually located?
And is it ok to have changed the relay to this one with 30 30 even though old one was 30 20..see specs
Also it's 277 instead of 240 vac

 

That relay is fine. That is the maximum voltage that it can switch.

In the picture..... you need to check from C to C for continuity and from TL to C to make sure the thermal link is closed or shorted. Continuity is checked with power shut off to the unit.

 

I did the ohms test an All were fine.

I saw though that half the coils were frosted up .

Is this a sign reversing valve isn't functioning or low freon or defrost board?

Compressor was warm an pipe going to reversing valve warm up to it an the rest after it were cold
Not sure why half is frosted or the valve at bottom of coil.

Odd that this happens after changing relays out too..it was colder that day an I didn't see then frozen over like this.

Still not sure what to look at on heat strips next either.

Any info is appreciated

 

Frost halfway up the coil usually means low on refrigerant.
What kind of unit is this.... a packaged unit ?
Post the model number for it.

Using this picture. The terminal block is 240vac. The two black wires (B leg) go directly to one side of the heat strips. So one side of the heating strips is always live. When those relays close.... they send the other half (A leg) to the other side of the heat strips. If you are not getting 240VAC on the heat strips (C to C in post 6).... the relays are not closing. The relays need 24VAC from the white wire to what looks like brown to close.

See if you have 24VAC to the relays when the heat strips should be on. If not..... you need to trace those wires and find where the power is getting lost. I'd imagine white is the W terminal and the brown is Common.

 

RuModel # 50hs-024-311a
Package unit
I'll trace the wires.
I do hear a light faint bus like sound near relays in e heat mode.

Is there a sequencer or a limit switch on this ?

 

Tech was there an narrowed it down to double 30 amp breaker. At box.

Is Eaton ok to replace Bryant brakers with ?
I do recall using them in the panel here when redoing some electrical.

Low Freon was why coil froze...

 

So then you didn't have 240v to the connecting block.
Eaton BR breakers can replace Bryant BR breakers.

 

No go..
I put new one in an still no heat
Ohms from power wire to relays are fine an other wire in relays to strip ok too ?

Hmm I did notice a slight hum for a moment at relays then a kick in Buzz like noise that remained .
I guess I'll have to check voltage from breaker as you said

Any way to test relays ?

This should be simple with just 2 feeds 2 relays a heat strip an power from thermostat but it's not .


AN yes I cleared the mud dobber nest..lol.

 

Here is diagram to it .
Any info is appreciated.

 

Going back to post 6.

Are you getting 240 volts to the spot that PG labeled C ( left) and TL?

 

Yess 128 on both legs at strip

An 27.3 at the white coming to relay ..it connects to tan in thermostat.

I can't get anything off the 24vac brown common wire though .an it attached to blue them to tstat ..

It's located in a different junction on tstat.

I tested ohms on both brown an white from relay to tstat an both were fine ..


Shouldn't this common wire be hot at relay?

 

I think it has to do with the darn relays!!!!

I put old bk in an no buzz an a lol smoke like the coils getting hot !!
A good sign!!




HOW DO I TEST THE ORIGINAL RELAYS!




I'M NOT SURE THOSE REPLACEMENTS WERE CORRECT ..!

NO HUMMING NOISE THIS TIME BUT I NEED TO BE SURE OLD RELAYS ARE FUNCTIONAL ..OR I'LL HAVE TO GET IDENTICLE REPLACEMENT .

 

We're you able to identify the two low voltage terminals on each relay?

Kinda sounds like you connected a high voltage wire to the low voltage coil.


On another note...

120 volts from each leg to ground doesn't prove that you have 240 volts to the heat strip.

Did you see 240 volts between the two terminals that PJ labeled for you?

 

Yes .Tested directly at wires to heat strip,after relay and at wires before relay coming from breaker.

Yes COILS DID HEAT ON 1 SIDE!!...ill have to look at other ..
ORIGINAL Relays
No buzz

The 2 low voltage were tested yes white had 27.3v ..wasnt able to get anything off brown
Both had no breaks coming from thermostat to unit or from unit connections to relays.

 

In emergency heat I am seeing only one side of the coils heat up.
Arent they both supposed to be ?
I did check ohms an voltage an it's getting the 240.
Any info is appreciated

 

Here are a few pics .The one under electrical is not on

 

Also should I be reading anything at the common wire to the relays? The white reads 27 v but common has nothing .
It traces bk to thermostat at common..

 

I combined your two threads. Starting a new one on the same exact topic is not helpful.

You need to be careful running the strips too long without proper airflow or they can burn up. When you see it start to glow red... that's a hot spot and not good for the coil.

We're going around in circles now. I've posted diagrams to follow and exact directions to check the relays and that circuit back in post 8.


When 24vac is applied to the two coil terminals..... the C and NO (common and normally open) contact closes.

 

You have two low voltage wires on the relay. You have brown which is common. There should be nothing measured between brown and ground. Then you have the white wire. When you measure 24v from white to brown or white to ground..... the relays should be active. The W wire gets it's 24vac directly from the thermostat when it's calling for heat strips.

The brown wire needs to connect to C at the wiring termination area. There is an additional wire from C to the thermostat.

 

Thanks.
Then I'm fine on the common .

An heat strip is likely hot on both just no bright hotspots on inside one I guess.

Hopefully new breaker was all it needed.
But I'm still stumped at that LOUD continual buzz off those replacement relays..[no longer on it]

Thank you again

 

Update on relays !

Took the replacements bk to dealer an a tech there ohms tested them along with a brand new one an BAM
DEFECTIVE RELAYS!

I WANTED TO TEST THEM IN THE BEGINNING!
They read in 500s an new one over 1000
​​​​​
I'll retest original ones to see if they are the same as over1000.

What ,if it did,can cause this new relay to become defective,if it was good before install?

too high amperage to it ?

It buzzed as a sign it was bad an tech testing system never even diagnosed it!!

 

500 what? Ohms?

That is a lot higher than the 16 Ohms found on standard coils.

 

I'll have to see if meter was set on on the 2000 or 200 ,etc reading
On 2 RELAY contacts that go to coil

Tested OFF unit

I'll get pic of it as being tested

But fact is they were same exact part an much different reading..

 

I've never had a defective heating relay with a bad coil. If you connect it to 24vac and the relay clicks.... it's good. The part that usually goes bad is the actual high voltage contacts.

 

On this meter ,set to 2000. .51. .other one I had had @20000.510

Guys measured

Over 1000 on his an 510 on mine

There are no other ohms that can be tested on this relay when off the unit an no power to it.

 

Zettler AZ2280-1A-22D The D stands for DC coil voltage. The resistance is around 500 ohms.

You somehow bought the wrong replacement relays. You need 24VAC coil relays.
Your original relays are 024A-1H11WF's which are 24VAC relays.
A 24vac coil will be around 106 ohms.

 

Yea they gave wrong part even though their system an tech said it's compatable ..


Yea but what I meant is the EXACT SAME 2 measured different when I brought it back an another new one exactly same was tested same part an maker .

The original one that was on unit wasn't involved..

it was 2 of the exact same by distributor

THAT SHOULD NOT HAPPEN .they should measure equally ..Tech tested both side by side 100% exact same ..500 off on one .
So what I did may have messed up original bought relay,to have changed the reading of 1000 to 500s . or it's a defective part ...

I'm ordering exact replacement online .

THIS couldn't have caused any damage to unit could it?