Results 1 to 6 of 6
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04-08-2005, 05:57 AM #1
Hot Gas defrost suction pressure regulation
I have a situation that we need to control the suction pressure (keep it elevated) during hot gas defrost. This is a retro fit install in order to get the room into the 34 degree range. Hot gas will be piped into a Tee set between the Sporlan distributor and the orifice. A liquid line solenoid valve will be present but, not de-energized during defrost.
The evap is an existing air defrost type ( 100,000 BTUH).
I need to keep the suction pressure elevated during defrost only. I was thinking about a suction stop evap pressure regulator but, then I woild only pump down the system and cycle off at the low pressure switch.
Any ideas?
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04-08-2005, 04:17 PM #2
Re: Hot Gas defrost suction pressure regulation
Hi 87Mustang,
Do you have one evaporator and one compressor for this system? Is your intent to provide hot gas defrost for the evaporator, or, hot gas bypass to control the evaporator pressure? You mentioned hot gas defrost, but also wanted to get the room in the 34F range.
Can you provide more details please?
Thanks,
US Iceman
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04-08-2005, 07:48 PM #3
Re: Hot Gas defrost suction pressure regulation
With hot gas defrost you also need to consider protecting the compressor from excessive back pressures.
A rule of thumb is to install a compressor pressure regulator if you install an evaporator pressure regulator
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04-08-2005, 10:53 PM #4
Re: Hot Gas defrost suction pressure regulation
Originally Posted by frank
I am working on a freezer at the moment that has a CPR attached.
It has hot gas defrost.
Refrigerant is r404a.
Looks like someone had screwed with the settings because I could not get compressor suction over about 25 psi and unit wasnt working properly.
Opened it up slightly and pressures and operation were now much better.
Just wondering if anyone new correct pressure and method to set.
Even though system now achieves correct temp I am not entirely convinced that it is correct.
Thanks.
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05-08-2005, 03:20 AM #5
Re: Hot Gas defrost suction pressure regulation
Originally Posted by 87mustang
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05-08-2005, 07:25 AM #6
Re: Hot Gas defrost suction pressure regulation
Hello 87 Mustang
Perhaps this link be useful for you
http://www.sporlan.com/90-40.pdf
Best regards
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