Carrier 50CR User Manual

Page 26

Balance Point Worksheet

-20

-10

Outdoor Air Temp (Deg F)

Building Heat Loss, 1000BTUH

Unit Integrated Heating Capacity,

1000BTUH

060

048

042

036

030

024

Based on Entering Indoor Air of 70 Deg. F and Rated CFM

C03008

Fig. 25 -- 50CR Balance Point Worksheet

Step 6—Refrigerant Circuit
Inspect all refrigerant tubing connections and the unit base for oil
accumulation annually. Detecting oil generally indicates a

refrigerant leak.
If oil is detected or if low performance is suspected, leak test all

refrigerant tubing using an electronic leak detector, or liquid--soap

solution. If a refrigerant leak is detected, refer to Check for
Refrigerant Leaks section.
If no refrigerant leaks are found and low performance is suspected,
refer to Checking and Adjusting Refrigerant Charge section.
Step 7—Indoor Airflow
The heating and/or cooling airflow does not require checking unless

improper performance is suspected. If a problem exists, be sure that
all supply-- and return--air grilles are open and free from

obstructions, and that the air filter is clean.
Step 8—Metering Devices--TXV & Accurater Piston
This unit uses 2 types of metering devices. The outdoor metering
device is a fixed orifice and is contained in the brass--hex body in the

liquid line feeding the outdoor coils. The indoor metering device is

a TXV--type device.
Step 9—Pressure Switches
Pressure switches are protective devices wired into control circuit
(low voltage). They shut off compressor if abnormally high or low

pressures are present in the refrigeration circuit. These pressure
switches are specifically designed to operate with Puron (R--410A)

systems. R--22 pressure switches must not be used as replacements

for the Puron (R--410A) system.

C99097

Fig. 26 -- Refrigerant Circuit

Step 10—Loss--of--Charge Switch
This switch is located on the liquid line and protects against low

suction pressures caused by such events as loss of charge, low

50C

R
50C