System Charge Adjustment; Charging: Weigh-In Method; Subcooling Charging And Refrigerant Adjustment In Cooling (Above 55°F Outdoor Temp.) - Bosch IDP Premium 18 SEER2 Series Installation Instructions Manual

Installation Instructions

12 System Charge Adjustment

The unit comes precharged from the factory with 7-8 lb-oz of
refrigerant. Follow Section 12 for charge adjustments i.e if components
have been replaced, or if there is a suspected leak.

12.1 Charging: Weigh-In Method

Weigh-in method is recommended anytime a system charge is being replaced.
Weigh-in method can also be used when power is not available to the equipment site
or operating conditions (indoor/outdoor temperatures) are not in range to verify
with the subcooling charging method.
Heat Pump Model
BRBA-36HWD1N1-M18
Table 13
12.2 Subcooling Charging and Refrigerant Adjustment In Cooling
(Above 55°F Outdoor Temp.)
1. Check the outdoor ambient temperatures.
Subcooling (in cooling mode) is the only recommended method of
charging above 55°F outdoor ambient temperatures. For outdoor ambient
temperatures below 55°F, use weigh-in charge method.
It is important to return in the spring or summer to accurately charge
the system in the cooling mode when outdoor ambient temperature is
above 55°F.
Outdoor
Temperature
Above 55ºF
120ºF
55ºF
Outdoor Temp1
Figure 23
For best results the indoor temperature should be kept between 70°F to 80°F.
2 0 |
Refrigerant Charge (lb-oz)
8-6
Outdoor
Temperature
Below 55ºF
55ºF
Outdoor Temp2
Bosch 18 SEER2 Series Inverter Ducted Packaged Heat Pump - BTC 761703103 A (11.2022)
80 ºF
70ºF
Indoor Temp
Figure 24
2. Stabilize the system.
After starting the system in cooling mode, short press "FORCE" button,
3.
and a " | — " symbol should appear. System may take 10 minutes to ramp up.
Operate the system for a minimum of twenty (20) minutes.
Figure 25
SW1 is not used.
After a twenty (20) minute stabilization period operating at 100%
capacity (72 Hertz ), maintain continuous operation while adjusting
refrigerant charge. After adjusting, operate system for a minimum of
fi ve (5) minutes for system to stabilize, otherwise repeat step 3.
20 MIN.
Figure 26
4. Calculate subcooling value on liquid line (According to Table 14)

Measured Liquid Line Temp. = ________ºF

Measured Liquid Line Pressure = _______ PSIG

Calculate subcooling value = ________ºF