System Charge Adjustment; Charging: Weigh-In Method; Subcooling Charging And Refrigerant Adjustment In Cooling; (Above 55°F Outdoor Temp.) - Bosch 19 SEER Series Operation Manual

2 0 | Bosch Inverter Ducted Packaged Heat Pump

12 System Charge Adjustment

T he unit comes precharged from the factory with 12-9 lb-oz of
refrigerant. Please measure superheat and subcooling, and add
or remove refrigerant accordingly.

12.1 Charging: Weigh-In Method

Weigh-in method is recommended for the initial installation, or 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
BRB-60HWD1N1-M19
Table 10

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.
I t 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 22
For best results the indoor temperature should be kept between 70°F to
80°F.
Data subject to change
Refrigerant Charge (lb-oz)
12-9
Outdoor
Temperature
Below 55ºF
55ºF
Outdoor Temp2
80 ºF
70ºF
Figure 23
2. Stabilize the system.
After starting the system in cooling mode, short press "FORCE"
3.
button, and a " | — " symbol should appear. System may take 10
minutes to ramp up. Operate the system for a minimum of twenty
(20) minutes.
SW2
FORCE
Figure 24
A fter a twenty (20) minute stabilization period operating at
100% capacity (60 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 25
4. Calculate subcooling value on liquid line (According to Table 11)

Measured Liquid Line Temp. = ________ºF

Measured Liquid Line Pressure = _______ PSIG

Calculate subcooling value = ________ºF
Installation & Operation Manual
Indoor Temp
03.2019 | BTC 761701105 A