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

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14 System Charge Adjustment

14.1 Charging: Weigh-In Method

Use weigh-in method during 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.
Model Factory Charge
3 Ton 7 lbs 9 oz
5 Ton 10 lbs 10 oz
Table 5
The factory charge in the outdoor unit is suffi cient for 15 feet of standard
size interconnecting liquid line.
New Installations — Calculating additional charge for lineset greater than 15
ft.
1. Total Line Length (ft) = _________(a)
2. Standard Lineset (ft) =
3. (a) minus (b) = _________(c)
4. Refrigerant Multiplier = 0.6 oz/ft (d)
5. Refrigerant Adder (c*d) = _________(e)*
*If lineset is less than 15 ft, (e) = 0
Sealed-System Repairs — Calculating total system charge.
1. Total Line Length (ft) = _________(a)
2. Standard Lineset (ft) =
3. (a) minus (b) = _________(c)
4. Refrigerant Multiplier = 0.6 oz/ft (d)
5. Refrigerant Adder (c*d) = _________(e)*
6. Factory Charge (namplate) = _________(f)
7. Total System Charge (e+f) = ________ _
*If lineset is less than 15 ft, (e) = 0
The only mode approved for validating system charge is while in Cooling
"Force Mode". Outdoor temperature must be between 55°F and 120°F
with indoor temperature kept between 70°F and 80°F.
Data subject to change
Charge multiplier for
interconnecting refrigerant
tube length
0.6 oz/ft
0.6 oz/ft
15 (b)
15 (b)
14.2 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 55ºF outdoor ambient temperatures.
For outdoor ambient temperatures below 55ºF 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
55ºF.
Outdoor
Temperature
Above 55ºF
120ºF
55ºF
Outdoor Temp1
Figure 38
For best results, the indoor temperature should be kept between 70ºF and
80ºF during the install.
80 ºF
70ºF
Indoor Temp
Figure 39
2. Ensure Sections 7,8,9,10,11,12 and 13 have been completed.
Installation Instructions
Outdoor
Temperature
Below 55ºF
55ºF
Outdoor Temp2
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