Heating Mode - Bosch LM024 Installation, Operation And Maintenance Manual

12 | SEQUENCE OF OPERATION
Heating Mode
Heating operation follows the same sequence as
cooling only without the "O" terminal. During
heating operation if the thermostat calls for
auxiliary heat ("W1"), the fan ramps up to auxiliary
heat air flow immediately and the electric heaters
are energized (if installed) along with the
compressor. Note that if the unit compressor locks
out for any reason at this time, the electric heaters
will continue to function normally.
Figure 13: Refrigerant Charge, Line Sizing and Capacity Multiplier Chart
SYSTEM
Factory
R410A
MODEL
Charge
(Oz)*
SM024 80
SM036 86
SM048 88
SM060 115
SM070 127
CAPACITY MULTIPLIER
Example 1:
Model SM036 with 45ft of equivalent length of 3/8" O.D Liquid
Line. Total system charge= Factory charge + (45ft - 25 ft) x .60
oz/ft Total System Charge = 93 oz + (20ft x .60 oz/ft) = 105 oz.
Additional 12 oz of R410A refrigerant required.
Figure 14: Liquid Line Charge Per Linear Foot
R410A oz per foot
8 733 920 847 (2014/01)
Refrigerant Line O.D. Size (Based on Equivalent Line Length)
25 FT. 35 FT.
LIQ. SUC. LIQ.
3/8 3/4 3/8
3/8 3/4 3/8
3/8 7/8 3/8
3/8 1-1/8 3/8
3/8 1-1/8 3/8
1.00 .995
Liquid Line Size, O.D.
1/4 5/16 3/8
.25 .44 .60
Subject to change without prior notice
Emergency heat (W2/EM) energizes the
emergency heat relay in the heater control box,
bringing on all of the heating elements at once. The
fan immediately ramps up to full electric heat air
flow.
As in cooling, once the thermostat is satisfied, the
fan will ramp back down over a period of 30
seconds.
45 FT. 50 FT.
SUC. LIQ. SUC. LIQ.
3/4 3/8 3/4 3/8
3/4 3/8 3/4 3/8
7/8 3/8 7/8 3/8
1-1/8 3/8 1-1/8 3/8
1-1/8 3/8 1-1/8 3/8
0.990 0.990
Example 2:
Model SM060 with 10ft of equivalent length of 3/8" O.D
Liquid Line. Total system charge= Factory charge + (25ft -
10ft) x .60 oz/ft Total System Charge = 150 oz + (15ft x .60
oz/ft) = 141 oz. Additional 12 oz of R410A refrigerant
required.
1/2 5/8
1.15 1.95
LM Series Heat Pump AH
Suct. Line
Riser Max.
75 FT
SUC. LIQ. SUC.
3/4 3/8 7/8
7/8 3/8 7/8
7/8 3/8 7/8
1-1/8 3/8 1-1/8
1-1/8 3/8 1-1/8
0.980
LM Series Heat Pump AH
3/4
3/4
7/8
7/8
7/8