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not sure what's wrong richard_ln 05-14-2008
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Posted by on May 14, 2008, 9:25 am
Most of my work has been new construction and very little service tech
so forgive me if this is too simple. My ex-wife called me a few days
ago and said her heat pump wasn't cooling. She said someone replaced
the compressor, which made it much better, but it's still not cooling
like it should. So I thought that unless I want to give her even more
of my hard earned money, I better load up the truck and head over.

Here's what I found. It's a 3 ton 10 seer HEIL split system heat pump
with a TXV. New copeland recip compressor and new dual cap. Coils
are clean, filter is clean. I put the guages on and that's when I got
a little confused.


outside air temp - 81
inside air temp = 78
Outdoor humidity: ~70%

Suc Pressure - 64
Suc temp - 80

Liq Pressure - 200
Liq temp - 87

Condenser TD - 13
Evaporator TD - 14

My handy Trane charging chart shows it being slightly overcharged....
but shouldn't be enough to give me such a low TD across the evap.
Rather than just start fiddling with the charge I thought I might want
to actually try to figure out what's wrong with it.

The only other thing out of the ordinary is the condenser fan was
replaced with one that's 75 rpm faster. It calls for a 1075 rpm and
has a 1150. In my brief experience I believe that won't have a big
effect.

any ideas?

Posted by Noon-Air on May 14, 2008, 10:07 am

> Most of my work has been new construction and very little service tech
> so forgive me if this is too simple. My ex-wife called me a few days
> ago and said her heat pump wasn't cooling. She said someone replaced
> the compressor, which made it much better, but it's still not cooling
> like it should. So I thought that unless I want to give her even more
> of my hard earned money, I better load up the truck and head over.
>
> Here's what I found. It's a 3 ton 10 seer HEIL split system heat pump
> with a TXV. New copeland recip compressor and new dual cap. Coils
> are clean, filter is clean. I put the guages on and that's when I got
> a little confused.
>
>
> outside air temp - 81
> inside air temp = 78
> Outdoor humidity: ~70%
>
> Suc Pressure - 64
> Suc temp - 80
>
> Liq Pressure - 200
> Liq temp - 87
>
> Condenser TD - 13
> Evaporator TD - 14
>
> My handy Trane charging chart shows it being slightly overcharged....
> but shouldn't be enough to give me such a low TD across the evap.
> Rather than just start fiddling with the charge I thought I might want
> to actually try to figure out what's wrong with it.
>
> The only other thing out of the ordinary is the condenser fan was
> replaced with one that's 75 rpm faster. It calls for a 1075 rpm and
> has a 1150. In my brief experience I believe that won't have a big
> effect.
>
> any ideas?

Without laying on of hands, my best guess would be to first pump down the
system, put in a bi-flow filter dryer, blow out the lines with N2 to clear
out any debris left from the old compressor, then clean the TXV screen, seal
the system back up, pull a 400micron vacuum, and re-charge with virgin
refrigerant. Start by weighing in the factory condenser charge, then balance
with SH/SC

Let us know how it works out.


Posted by on May 14, 2008, 10:26 am
>
>
>
>
>
>
> > Most of my work has been new construction and very little service tech
> > so forgive me if this is too simple. =A0My ex-wife called me a few days
> > ago and said her heat pump wasn't cooling. =A0She said someone replaced
> > the compressor, which made it much better, but it's still not cooling
> > like it should. =A0So I thought that unless I want to give her even more=

> > of my hard earned money, I better load up the truck and head over.
>
> > Here's what I found. =A0It's a 3 ton 10 seer HEIL split system heat pump=

> > with a TXV. =A0New copeland recip compressor and new dual cap. =A0Coils
> > are clean, filter is clean. =A0I put the guages on and that's when I got=

> > a little confused.
>
> > outside air temp - 81
> > inside air temp =3D 78
> > Outdoor humidity: ~70%
>
> > Suc Pressure - 64
> > Suc temp - 80
>
> > Liq Pressure - 200
> > Liq temp - 87
>
> > Condenser TD - 13
> > Evaporator TD - 14
>
> > My handy Trane charging chart shows it being slightly overcharged....
> > but shouldn't be enough to give me such a low TD across the evap.
> > Rather than just start fiddling with the charge I thought I might want
> > to actually try to figure out what's wrong with it.
>
> > The only other thing out of the ordinary is the condenser fan was
> > replaced with one that's 75 rpm faster. =A0It calls for a 1075 rpm and
> > has a 1150. =A0In my brief experience I believe that won't have a big
> > effect.
>
> > any ideas?
>
> Without laying on of hands, my best guess would be to first pump down the
> system, put in a bi-flow filter dryer, blow out the lines with N2 to clear=

> out any debris left from the old compressor, then clean the TXV screen, se=
al
> the system back up, pull a 400micron vacuum, and re-charge with virgin
> refrigerant. Start by weighing in the factory condenser charge, then balan=
ce
> with SH/SC
>
> Let us know how it works out.- Hide quoted text -
>
> - Show quoted text -

Will do. Thanks for your help.

Also, I forgot to mention that I heard a slight gurgling noise in the
liquid line, before the TXV. To me, that suggests an undercharge
because there's not a solid column of refrigerant at the TXV. That
was part of my confusion... a chart reading an overcharge but symptoms
(gurgling) indicating undercharge.





Posted by Noon-Air on May 14, 2008, 10:53 am

>
>
>
>
>
>
> > Most of my work has been new construction and very little service tech
> > so forgive me if this is too simple. My ex-wife called me a few days
> > ago and said her heat pump wasn't cooling. She said someone replaced
> > the compressor, which made it much better, but it's still not cooling
> > like it should. So I thought that unless I want to give her even more
> > of my hard earned money, I better load up the truck and head over.
>
> > Here's what I found. It's a 3 ton 10 seer HEIL split system heat pump
> > with a TXV. New copeland recip compressor and new dual cap. Coils
> > are clean, filter is clean. I put the guages on and that's when I got
> > a little confused.
>
> > outside air temp - 81
> > inside air temp = 78
> > Outdoor humidity: ~70%
>
> > Suc Pressure - 64
> > Suc temp - 80
>
> > Liq Pressure - 200
> > Liq temp - 87
>
> > Condenser TD - 13
> > Evaporator TD - 14
>
> > My handy Trane charging chart shows it being slightly overcharged....
> > but shouldn't be enough to give me such a low TD across the evap.
> > Rather than just start fiddling with the charge I thought I might want
> > to actually try to figure out what's wrong with it.
>
> > The only other thing out of the ordinary is the condenser fan was
> > replaced with one that's 75 rpm faster. It calls for a 1075 rpm and
> > has a 1150. In my brief experience I believe that won't have a big
> > effect.
>
> > any ideas?
>
> Without laying on of hands, my best guess would be to first pump down the
> system, put in a bi-flow filter dryer, blow out the lines with N2 to clear
> out any debris left from the old compressor, then clean the TXV screen,
> seal
> the system back up, pull a 400micron vacuum, and re-charge with virgin
> refrigerant. Start by weighing in the factory condenser charge, then
> balance
> with SH/SC
>
> Let us know how it works out.- Hide quoted text -
>
> - Show quoted text -

Will do. Thanks for your help.

Also, I forgot to mention that I heard a slight gurgling noise in the
liquid line, before the TXV. To me, that suggests an undercharge
because there's not a solid column of refrigerant at the TXV. That
was part of my confusion... a chart reading an overcharge but symptoms
(gurgling) indicating undercharge.


You may have air and nons in the system that are giving you false readings.



Posted by Stormin Mormon on May 15, 2008, 9:00 am
Very possible you have a load of air in the system.

I'm learning to make good use of my IR thermometer. A hot filter dryer
(after the condensor) means that the condensor needs cleaning. The guys on
the list groan, roll their eyes, and call me a hack. But I've learned that
even a clean looking condensor can be way below efficiency.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
.



Also, I forgot to mention that I heard a slight gurgling noise in the
liquid line, before the TXV. To me, that suggests an undercharge
because there's not a solid column of refrigerant at the TXV. That
was part of my confusion... a chart reading an overcharge but symptoms
(gurgling) indicating undercharge.






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