Vogt P-24AL, Service Manual

Page: 13 / 149

P24AL & P34AL Service Manual
INTRODUCTION
12/2016
1-3
Special Precautions to Be Observed When Charging Refrigeration Systems. Only technically-
qualified persons, experienced and knowledgeable in the handling of anhydrous ammonia refrigerant
and operation of refrigeration systems, should perform the operations described in this manual. All
local, federal, and EPA regulations must be strictly adhered to when handling ammonia (R-717)
refrigerant. See “Material Safety Data Sheet”, MSDS Code No. 5B81-83.
If a refrigeration system is being charged from refrigerant cylinders, disconnect each cylinder when
empty or when the system is fully charged. A gage should be installed in the charging line to
indicate refrigerant cylinder pressure. The cylinder may be considered empty of liquid R-717
refrigerant when the gauge pressure is 25 pounds or less, and there is no frost on the cylinder. Close
the refrigerant charging valve and cylinder valve before disconnecting the cylinder. Loosen the
union in the refrigerant charging line--carefully to avoid unnecessary, excessive or illegal release of
refrigerant into the atmosphere.
! CAUTION !
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, over-filling it, and
possibly causing the cylinder to rupture because of pressure from expansion of the liquid
refrigerant brought on by an increase in temperature.
! CAUTION !
Always store cylinders containing refrigerant in a cool place. They should never be exposed to
temperatures higher than 120

F and should be stored in a manner to prevent abnormal mechanical
shocks.
Also, transferring refrigerant from a refrigeration system into a cylinder can be very dangerous and is
not recommended.
! CAUTION !
It is not recommended that refrigerant be transferred from a refrigeration system directly into
a cylinder. If such a transfer is made, the refrigerant cylinder must be an approved, CLEAN
cylinder--free of any contaminants or foreign materials--and must be weighed continuously to
assure contents do not exceed net weight specified by cylinder manufacturer or any applicable
code requirements.
! CAUTION !