Start Up And Operation; Leak Test; System Evacuation - Emerson KHZ506 User Manual

Start Up and Operation

Leak Check
The unit has been leaktested and QA approved from the factory. However, due to handling and shipping
the entire refrigeration systemmust be tested for leaks. Failure to carry out leak test can result to
undesirable system performance.
Step-by-step:
1. Open both the liquid and suction service valves.
2. Ensure the solenoid valve is energized and open, if available.
3. Pressurize the system to300 psig/21 Bar maximum with dry nitrogen.
4. Allow dry nitrogen to reach all parts of the system.
5. Check all joints and components using soap/bubble test or with an electronic leak detector.
6. Wait for atleast an hour to ensure the system is holding the pressure and is found to beleaked proof,
if the system loses any pressure over the course of 30 minutes to1 hour, then it is a sure indication
that the system is leaking
If leak has been detected somewhere on the system, relief the pressure and repair the leak. For an
effective installation, the system must be leak tight.

System Evacuation

Evacuating a refrigeration system serves two primary objectives: (1) remove non-condensable and
(2) remove water vapor or dehydrate the system.
Air and moisture are detrimental to system operation. The successful long-term operation of the system
depends on thoroughly conditioning them before charging with refrigerant and the losses associated
with improper evacuation erodes system efficiency as well as costly for the installers.
A 2-stage vacuum pump along with a micron gauge is recommended in performing evacuation. The
quality of vacuum is not determined by time – a micron gauge must be used since it is the only device
that accurately reads the vacuum pressure during the evacuation process.
REMINDER: Do not use the system compressor as a vacuum pump and never operate the compressor
while the system is in vacuum.
(best practice) to be implemented on all our installations.
Note
that the following procedure is based upon achieving an actual system vacuum
standard and it is NOT TIMEDEPENDENT!
Step-by-step:
1. Open both the liquid and suction service valves.
Ensure the solenoid valve is energized and open, if available.
2.
Connect vacuum pump to the liquid and suction service valves.
3.
Start the vacuum pump and then open the service valves.
4.
Perform triple evacuation process as follows:
5.
Vacuum until a pressure of 500 microns is reached — at which time the vacuum
i.
should be broken with the refrigerant to be used in the system through a drier
until the system pressure rises to 20 psig
Repeat this vacuuming process again.
ii.
Evacuate the entire system to 500 microns (minimum recommended). Evacuate
iii.
the system below 500 microns may enhance the reliability of system.
Emerson Climate Technologies recommends Triple Evacuation Process
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