19
Installation of the Unit
Vacuum and Gas Leakage Inspection
CAUTION!
Do not purge the air with refrigerants but use a vacuum pump to vacuum the installation!
There is no extra refrigerant in the outdoor unit for air purging!
(1). Remove the caps of the liquid valve, gas valve and also the service port.
(2). Connect the hose at the low pressure side of the manifold valve assembly to the service
port of the unit’s gas valve, and meanwhile the gas and liquid valves should be kept
closed in case of refrigerant leak.
(3). Connect the hose used for evacuation to the vacuum pump.
(4). Open the switch at the lower pressure side of the manifold valve assembly and start the
vacuum pump. Meanwhile, the switch at the high pressure side of the manifold valve
assembly should be kept closed, otherwise evacuation would fail.
(5). The evacuation duration depends on the unit’s capacity, generally, 20 minutes for the
18K units, 30 minutes for the 24 units. And verify if the pressure gauge at the low
pressure side of the manifold valve assembly reads -1.0Mp (-75cmHg), if not, it indicates
there is leak somewhere. Then, close the switch fully and then stop the vacuum pump.
(6). Wait for some time to see if the system pressure can remain unchanged, 5 minutes for
the 18K~24K units. During this time, the reading of the pressure gauge at the low
pressure side can not be larger than 0.005Mp (0.38cmHg).
(7). Slightly open the liquid valve and let some refrigerant go to the connection pipe to
balance the pressure inside and outside of the connection pipe, so that air will not come
into the connection pipe when removing the hose. Note that the gas and liquid valve can
be opened fully only after the manifold valve assembly is removed.
(8). Place back the caps of the liquid valve, gas valve and also the service port.
1. Vacuum
Hose with the valve pin
gauge manifold
pipe
pipe
VAC valve
Vacuum pump
Service port
Low pressure gauge
High pressure gauge
Gauge manifold kit
Fig.25
Содержание SDVH12M-A1NBI/P
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