Larkin condensors

[mpr73]

Just throwing this out there for you guys. Over the last year my company has installed 4-5 new walk in coolers. ( evaps, TXV, line sets and cond.)

And every last one has had a bad headmaster right out of the gate. The latest one is a Larkin m: LHT050X60CFM, new style with the micro channel coil. Once everything is up and running my liquid side hangs about 140PSI on a 180 valve. Check condensor coil and half is warm and half is cool. ( 24lbs of 404-a) Site glass flashing a bit. Add a fan cycler and of course glass clears during fan off. Fan cycles on glass remains clear. Ambient was 30*

We have done this a few times like I said til we can get a new head master, new valve diverts flow as needed and maintains the 180... Just wondering if anyone else has been having these issues right out of the gate.

[ryan1088]

Interesting. What brand valves??

[mpr73]

Sporlan OROA-5-180

[bunny]

From my experience in working for the valve company in question and being in the industry for nearly 40 years......almost without exception when someone finds multiples of the same component all failing on startup, there is normally some other explanation besides it being a defective component.

Just saying.....

[y7turbo]

How are you coming up with the additional charge to flood the condenser using the microchannel coil?

[jpsmith1cm]

From my experience in working for the valve company in question and being in the industry for nearly 40 years......almost without exception when someone finds multiples of the same component all failing on startup, there is normally some other explanation besides it being a defective component.

Just saying.....

This makes a LOT of sense.

One failure? Yeah, it happens. Multiple failures? Something fishy is going on.

How are you coming up with the additional charge to flood the condenser using the microchannel coil?

I know that Heatcraft published a chart that just gave a flooding charge value for their microchannel coils.

I suppose that Larkin would, too.

[codgy]

It does sound like system charge is the culprit. You must charge to full sight glass then add additional chagrge for low ambient operation. If sight glass was not full then there was not enough charge to flood condenser which would then lower condenser pressure below valve setting. I must admit that 24 lb is about what I normally charge that size unit when lines are under 50'.

[ryan1088]

This makes a LOT of sense.

One failure? Yeah, it happens. Multiple failures? Something fishy is going on.



I know that Heatcraft published a chart that just gave a flooding charge value for their microchannel coils.

I suppose that Larkin would, too.

I thought Larkin was Heatcraft?

[Tommy knocker]

Flashing glass = big red flag.

[jpsmith1cm]

I thought Larkin was Heatcraft?

I can't keep track of who is who.

Bohn is Heatcraft, I know.

Other than that, I write down the numbers and somebody else deciphers who owns who and who supplies what parts.

[y7turbo]

I know that Heatcraft published a chart that just gave a flooding charge value for their microchannel coils.

I suppose that Larkin would, too.

In sure they do JP. Lets see how the OP calculated the charge.

[2sac]

Larkin is also Heatcraft. Their nameplates need special deciphering

[phxhvac]

Heatcraft owns Bohn, Larkin, Climate Control, and Chandler. Check the flooded charge.

Sent from my DROID RAZR using Tapatalk 2

[mpr73]

Charge was calculated by size of receiver height and diameter. and mounting direction ( vertical or horizontal) We all have books and literature from united refrigeration and refrigeration research. That will give you the capacity of it. That is how our company and a few of the 20 plus year guys have always said to do it.
At my previous company I was always told to charge to a til glass.

I have been hesitant lately of over charging I had one case over the summer that I over charged by about 6lbs and got a call back on the WIF not holding temp. But that was charging til a clear glass and it bit me.

So now Ive been trying to use as literature as possible when charging. I also do agree with you guys that once ok but multiple times odds are that it is more than likely not a equipment issue. But everything was installed and charged to the letter so that is the part that makes it odd. and when a new headmaster is installed everything acts properly.

[2sac]

And I believe Lennox owns Heatcraft

[carmon]

been in the trade over 30 years...... work on lots of refrigeration..... maybe changed 3 headmasters in my life...... they usually don't cause a problem......

[MechanicallyInclined]

Yes, Lennox owns Heatcraft. One brand that wasn't mentioned was Kysor/Warren, also under Heatcraft. Rumor has it that Lennox will roll out a Heatcraft Service soon, specializing in anything Com. Ref. What do you guys think? Was not the Service Experts and National Accounts Services businesses enough?!

[icemeister]

The only written info I ever seen on low ambient charge requirements for Heatcraft units with the HyperCore condenser coils is this FAQ bulletin (See p.6):

Heatcraft 1/2 - 6 HP Units with Hypercore FAQ

As you can see from this, 2-3 pounds is about it for even their larger units.

[y7turbo]

As you can see from this, 2-3 pounds is about it for even their larger units.

Thats what heatcraft said when I called a while back. I was installing a new condensing unit but there was nothing in the manual on how to calculate the charge for the headmaster on the microchannel coils. He said there is two ways, clear the glass and add 3 pounds, or charge to 90% receiver capacity.

[jpsmith1cm]

I just saved that pdf to my phone.

Then I can just look it up...