Vogt P118F/HE100, Service Manual

Page: 48 / 126

05TA Service Manual
START-UP AND OPERATION
7/19/13
5-4
! CAUTION !
If it should become necessary to add refrigerant to the system,
charging valve (28) is provided for this purpose. Be sure to follow
all local and federal regulations regarding the handling of
refrigerants and their illegal emission into the atmosphere.
! CAUTION !
Check the refrigerant level after the machine has operated for a few cycles. It should be slightly
above the minimum operating level, as indicated on the receiver, a few minutes prior to start of a
thawing period. If this level is low at this time, sufficient refrigerant should be added to the system
to raise the level above this point. Add only a small quantity (10 lbs. or less) at a time and operate
the machine several cycles to check the level before adding additional refrigerant. Refrigerant may
be added as a liquid through the charging valve (28) only while the machine is operating. It is
important that no air or other non-condensable gas enter the system when charging refrigerant into
the unit. It is also possible to check the refrigerant level by pumping machine down (See page 9-15).
When the machine is pumped down, a liquid level should be observed in the gage glass on the
receiver.
Adding Refrigerant.
When adding refrigerant, use the following procedure:
1. Make connection between charging valve and refrigerant cylinder using hose or pipe
suitable for R-22 or R-404a service. See instruction card attached to refrigerant cylinder.
2.
Open valve on R-22 or R-404a cylinder and purge air out of charging line at the charging
valve connections.
3.
Open charging valve.
4.
Refrigerant can be added only during the freeze cycle. The charging valve must be
closed when the freezer is in a harvest.
In order to check the total charge in the system, it is necessary to transfer all refrigerant to the
receiver. A total pumpdown procedure should be performed.
See the name plate for the approximate refrigerant charge for the machine. Remember that the total
charge will vary for air-cooled machines with remote air-cooled condensers.
! DANGER !
Immediately close system charging valve at commencement of
defrost or thawing cycle if refrigerant cylinder is connected. Never
leave a refrigerant cylinder connected to system except during charging
operation. Failure to observe either of these precautions can result in
transferring refrigerant from the system to the refrigerant cylinder,
overfilling it, and possibly causing the cylinder to rupture because
of pressure from expansion of the liquid refrigerant.
! DANGER !