Air innovations 99H0360-10, Инструкция по установке, эксплуатации и обслуживанию, Страница: 48 / 85

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Refrigerant Charging
NOTE: Models DS, and WGS utilize a Headmaster control valve to control head pressure
at low ambient applications, therefore require a specific initial charging procedure as
outlined below.
Determining the amount of charge
–
Low ambient and extreme low ambient (XLA)
systems - When “refrigerant side” head pressure control is utilized on a system, one of the most
important factors is determining the total system refrigerant charge. While on most packaged
units the amount of charge is listed on the unit, the required charge for a field built-up system
cannot be listed by the manufacturer. Charge is usually added when the system is started up until
“proper” system performance is reached. However, this is not satisfactory and if the system is to
function properly year-round, the correct amount of extra charge must be calculated ahead of
time.
**SEE PAGE 50 FOR DESIGNED AMOUNTS OF REFRIGERANT CHARGE
FOR YOUR SPECIFIC MODEL SYSTEM**
Procedures for Charging System with Head Pressure Control
NOTE: When charging any system with head pressure control the outdoor ambient
temperature must be known.
Charging of Systems with Head Pressure Control in temperatures above 70° F
(21°C) --After normal evacuation procedures:
1. Connect refrigerant cylinder to liquid line service valve port.
2. Charge liquid refrigerant into the high side of the system. Weighing the charge is
recommended.
3. Remove the refrigerant drum and connect it to the suction service valve.
4. Charge refrigerant vapor into the low side. Do not allow liquid refrigerant into the low
side.
5. Start the system.
6. Observe sight glass (factory-installed) to see if system is filling with refrigerant for normal
refrigeration cycle.
CAUTION
BUBBLES IN THE SIGHT GLASS CAN BE CAUSED BY FLASHING DUE TO PRESSURE DROP FROM
PIPE OR ACCESSORY LOSSES, ETC.
7. If the Sight glass shows bubbles, more refrigerant may be required, while allowing
sufficient time for the refrigerant to stabilize and clear the Sight glass. Use supplied
information on the following pages for proper final charge
.