Bosch LM024, LM060, LM036, LM070, LM048 Operating Instructions Manual

LM CS Series Heat Pump

LM024 | LM036 | LM048 | LMO60 | LM070

Installation, Operation and Maintenance Manual

8 733 920 847 (2014/01)

2 | LM CS Series Heat Pump

CONTENTS

CS/AH Pairing ................................................................... 3

Key to Symbols.................................................................. 3

Safety Warnings ................................................................ 3

LM CS Standard package.................................................... 4

GENERAL DESCRIPTION .................................................... 4

MOVING AND STORAGE ..................................................... 4

INITIAL INSPECTION .......................................................... 4

LOCATION......................................................................... 5

Condensing Section ..................................................... 5

Air Handler ................................................................. 5

INSTALLATION .................................................................. 5

CONDENSATE DRAIN ......................................................... 6

WATER PIPING .................................................................. 6

ELECTRICAL ...................................................................... 6

Safety Devices and the UPM Controller ........................... 7

COMFORT ALERT MODULE............................................... 10

OPTIONS......................................................................... 12

Pump Status Switch ................................................... 12

DPS Water Flow Proving ............................................. 12

Valve End Switch ....................................................... 12

Pump Relay............................................................... 12

SEQUENCE OF OPERATION .............................................. 13

Cooling Mode ............................................................ 13

Heating Mode............................................................ 13

APPLICATION CONSIDERATIONS...................................... 15

Well Water Systems ................................................... 15

Cooling Tower/Boiler Systems ..................................... 15

Geothermal Systems .................................................. 17

SYSTEM CHECKOUT ........................................................ 18

UNIT START-UP ............................................................... 18

MAINTENANCE................................................................ 19

UNIT CHECK-OUT SHEET .................................................. 20

TROUBLESHOOTING ........................................................ 21

OPERATING TEMPERATURES AND PRESSURES ................. 25

WIRING DIAGRAMS ......................................................... 30

DIMENSIONAL DRAWINGS ............................................... 31

NOTES ............................................................................ 32

LM CS Series Heat Pump8 733 920 847 (2014/01) Subject to change without prior notice

LM CS MODEL NOMENCLATURE

LM 024 - 1 CS C - F

SERIES WATER CONNECTIONS

LM F - Front

SIZE

COAX OPTIONS

024 C - Copper
036 N - Cupro-Nickel
048
060

CABINET CONFIGURATION

070 CS - Condensing Section

VOLTAGE DESIGNATIONS

1

- 208/1/60 & 230/1/60

Revision Level A

CS/AH Pairing | 3LM CS Series Heat

CS/AH PAIRING

UNIT MODEL

LM024-1CSC
LM036-1CSC
LM048-1CSC
LM060-1CSC
LM070-1CSC

Paired Air Handler

Unit 1 Unit 2

LM024-1AVX
LM036-1AVX
LM048-1AVX
LM060-1AVX
LM070-1AVX

LM024-1AHX
LM036-1AHX
LM048-1AHX
LM060-1AHX
LM070-1AHX

KEY TO SYMBOLS

Warnings

Warnings in this document are identified by
a warning triangle printed against a grey
background. Keywords at the start of the
warning indicate the type and seriousness
of the ensuing risk if measures to prevent
the risk are not taken.

The following keywords are defined and can be
used in this document:

• NOTE indicates a situation that could result in
damage to property or equipment.

• CAUTION indicates a situation that could
result in minor to medium injury.

• WARNING indicates a situation that could
result in sever injury or death.

• DANGER indicates a situation that will result in
severe injury or death.

Important Information

This symbol indicates important information
where there is no risk to property or people.

SAFETY WARNINGS

Before performing service or maintenance
operations on the system, turn off main
power to the unit. Electrical shock could

cause personal injury or death.

Installation and servicing of this equipment
can be hazardous due to system pressure
and electrical components. Only trained
and qualified personnel should install,
repair, or service the equipment.

All refrigerant discharged from this unit
must be recovered WITHOUT EXCEPTION.
Technicians must follow industry accepted
guidelines and all local, state, and federal
statutes for the recovery and disposal of
refrigerants. If a compressor is removed
from this unit, refrigerant circuit oil will
remain in the compressor. To avoid leakage
of compressor oil, refrigerant lines of the
compressor must be sealed after it is
removed.

R410A is flammable when exposed to open
flame. Recover all refrigerant prior to
brazing.

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4 | LM CS Standard package LM CS Series Heat Pump

1

2

LM CS STANDARD PACKAGE

Figure # 1

[1] LM Split Series Water-to-Air Heat Pump
Condensing Section

[2] Installation and Operation Manual

GENERAL DESCRIPTION

LM Split Series Water-to-Air Heat Pumps provide
the best combination of performance and
efficiency available. All units are performance
certified to American Heating and Refrigeration
Institute (AHRI) ISO Standard 13256-1. All LM
Water-to-Air Heat Pumps conform to UL1995
standard and are certified to CAN/CSA C22.1 No
236 by Intertek-ETL.

Split system heat pumps consist of two
independently installed sections allowing for
centralized air distribution while remotely locating
the section containing the compressor and water­to-refrigerant heat exchanger.

The Water-to-Air Heat Pumps are designed to
operate with entering fluid temperature between
20°F to 80°F in the heating mode and between
50°F to 110°F in the cooling mode.

50°F Minimum Entering Water Temperature
(EWT) for well water applications with sufficient
water flow to prevent freezing. Antifreeze
solution is required for all closed loop
applications.

Cooling Tower/Boiler and Geothermal
applications without antifreeze must have
means to protect against extreme conditions
and equipment failure. Frozen water coils are
not covered under warranty. Other equivalent
methods of temperature control are acceptable.

Several factory installed options are available:
Differential Pressure Switch (DPS) Water Flow
Proving Switch, Auxiliary Pump Relay, Zone Valve
and Internal Water Pump. See Pg#12 for more
detail.

Safety devices are built into each unit to provide
the maximum system protection possible when
properly installed and maintained.

MOVING AND STORAGE

If the equipment is not needed for immediate
installation upon its arrival at the job site, it should
be left in its shipping carton and stored in a clean,
dry area. Units must only be sto r ed or m o v ed in t h e
normal upright position as indicated by the “UP”
arrows on each carton at all times.

In the cooling mode, the air coil in the air handler
section serves as an evaporator and the water-to­refrigerant heat exchanger serves as a condenser.
In the heating mode, their roles are reversed.

In cooling mode, the refrigerant lines connecting
the two sections consist of one line carrying liquid
refrigerant and another carrying refrigerant vapor.
The liquid carrying line will be referred to as the
liquid line while the vapor carrying line will be
referred to as the suction line.

INITIAL INSPECTION

Be certain to inspect all cartons or crates on each
unit as received at the job site before signing the
freight bill. Verify that all items have been received
and that there are no visible damages; note any
shortages or damages on all copies of the freight
bill. In the event of damage or shortage, remember
that the purchaser is responsible for filing the
necessary claims with the carrier. Concealed
damages not discovered until after removing the
units from the packaging must be reported to the
carrier within 24 hours of receipt.

LM CS Series Heat Pump8 733 920 847 (2014/01) Subject to change without prior notice

Location | 5LM CS Series Heat

Vibration Pad is
recommended

LOCATION

To maximize system performance, efficiency and
reliability, and to minimize installation costs, it is
always best to keep the refrigerant lines as short
as possible. Every effort should be made to locate
the air handler and the condensing section as
close as possible to each other.

Condensing Section

Locate the condensing section in an area that
provides sufficient room to make water and
electrical connections, and allows easy removal of
the access panels, for service personnel to
perform maintenance or repair.

The condensing section is designed for indoor use;
however, if the condensing section must be
installed in an outdoors location where ambient
temperatures can fall below freezing, some form of
freeze protection should be employed such as a
freeze-stat and/or a pump timer/starter to prevent
possible condenser freeze-up and to optimize
overall system performance.

Air Handler

Locate the air handler unit in an indoor area that
allows easy removal of the filter and access panels,
and has enough room for service personnel to
perform maintenance or repair. Provide sufficient
room to make electrical and duct connections. If
the unit is located in a confined space such as a
closet, provisions must be made for return air to
freely enter that space.

Reference the Factory Manual for your AH, or
Air Handler section of this manual for detailed
installation and operation.

INSTALLATION

Loosen compressor mounting bolts.

NOTE: The installer should comply with all
local codes and regulations which govern
the installation of this type of equipment.
Local codes and regulations take precedent
over any recommendations contained in
these instructions. In lieu of local codes, the
equipment should be installed in
accordance with the recommendations
made by the National electric code, and in
accordance with the recommendations
made by the National Board of Fire
Underwriters.

Condensing Section

The condensing section should be mounted on a
vibration absorption pad on a cement slab or
similar support to provide a good base and some
degree of levelness. The cement pad should not
come in contact with the foundation or side of the
dwelling, because sound may be transmitted into
the residence. See Figure #2 below.

DO NOT remove the protective caps or plugs
from the service valves until the refrigerant
lines are run and ready for final connections.

Figure # 2

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6 | Condensate Drain LM CS Series Heat Pump

CONDENSATE DRAIN

Use cupra-nickel condenser in ground
water application due to possibility of
containing high mineral and corrosive
properties

Both the supply and discharge water lines will
sweat if subjected to low water temperature.
These lines should be insulated to prevent damage
from condensation. All manual flow valves used in
the system must be ball valves. Globe and gate
valves must not be used due to high pressure drop

Figure # 3

A drain line must be connected to the air handler
and pitched away from the unit a minimum of 1/8”
per foot to allow the condensate to flow away from
the unit.

This connection must be in conformance with local
plumbing codes. A trap must be installed in the
condensate line to insure free condensate flow.

Drain Pan is not internally sloped.

and poor throttling characteristics.

Never exceed the recommended water flow
rates, as serious damage or erosion of the
water-to-refrigerant heat exchanger could
occur.

Teflon tape sealer should be used when
connecting water piping connections to the units
to insure against leaks and possible heat
exchanger fouling.

A vertical air vent is sometimes required to avoid
air pockets. The length of the trap depends on the
amount of positive or negative pressure on the
drain pan. A second trap must not be included.

WATER PIPING

Supply and return piping must be as large as the
unit connections on the heat pump (See manual
Pg#10 for any line size at installation length longer
than 25 feet).

Never use flexible hoses of a smaller inside
diameter than that of the fluid connections
on the unit.

LM units are supplied with either a copper or
optional cupro-nickel condenser. Copper is
adequate for ground water that is not high in
mineral content.

Proper testing is recommended to assure the
well water quality is suitable for use with water
source equipment.

In conditions anticipating moderate scale
formation or in brackish water a cupro-nickel heat
exchanger is recommended.

Flexible hoses should be used between the unit
and the rigid system to avoid possible vibration.
Ball valves should be installed in the supply and
return lines for unit isolation and unit water flow
balancing.

ELECTRICAL

Refer to electrical component box layout.
(Figures #5,6)

Field wiring must comply with local and
national electric codes. Properly sized fuses
or HACR circuit breakers must be installed
for branch circuit protection. See unit
nameplate for maximum fuse or breaker
size.

Power to the unit must be within the
operating voltage range indicated on
the unit nameplate or on the
performance data sheet.

Operation of unit on improper line
voltage or with excessive phase
imbalance will be hazardous to the unit,
constitutes abuse and may void the
warranty.

LM CS Series Heat Pump8 733 920 847 (2014/01) Subject to change without prior notice

Electrical | 7LM CS Series Heat

4

5

3

2

15

6

7

8

1

10

12

14

13

11

9

1

2

3

4

5

6

78

9

10

11

1213

17

14

15

16

The unit is provided with a concentric knock-out
for attaching common trade sizes of conduit, route
power supply wiring through this opening.

Always connect the ground lead to the grounding
lug provided in the control box and power leads to
the line side of compressor contactor as indicated
on the wiring diagram (Figures#17 through #25,
Pg#30 through Pg#40).

[9] ECM Interface Board(Option, mounts on E-Box
cover)

[10] Comfort Alert Module (Option)
[11] DDC (Option)
[12] LonWorks Card (Option)
[13] Input Expansion Module (Option)
[14] Smart Start Assist (Option)
[15] Ground Lug

Safety Devices and the UPM Controller

Figure # 4 - Single Phase unit

Figure # 6 Typical UPM Board

[1] Board Power Indicator
[2] UPM Status LED Indicator
[3] Water Coil Freeze Protection Temperature

Selection [R30]
[4] Air Coil Freeze Protection Temperature

Selection
[5] UPM Board Settings
[6] Water Coil Freeze Connection
[7] Air Coil Freeze Connection

Figure # 5 EBox Cover

[1] Compressor contactor
[2] Energy Management System Relay (Option)
[3] Hot Gas Reheat Relay (Option)
[4] Cooling Relay
[5] Unit Protection Module (UPM)
[6] Terminal block Low-Voltage
[7] Auxiliary Relay (Option)
[8] Capacitor

[8] LED Status-Diagnostic Connection
[9] 24VAC Power Input
[10] Compressor Contact Output
[11] High Pressure Switch Connection
[12] Call for Compressor Y1
[13] Low Pressure Switch Connection
[14] 24VAC Power Common
[15] Condensate Overflow Sensor
[16] Dry Contact
[17] UPM Ground Standoff

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8 | Electrical LM CS Series Heat Pump

If the unit is being connected to a thermostat
with a malfunction light, this connection is made
at the unit malfunction output or relay. Refer to
Figure #6.

If the thermostat is provided with a malfunction
light powered off of the common (C) side of the
transformer, a jumper between “R” and “COM”
terminal of “ALR” contacts must be made.

If the thermostat is provided with a malfunction
light powered off of the hot (R) side of the
transformer, then the thermostat malfunction
light connection should be connected directly to
the (ALR) contact on the unit’s UPM board.

Each unit is factory provided with a Unit Protection
Module (UPM) that controls the compressor

operation and monitors the safety controls that
protect the unit.

Safety controls include the following:

• High pressure switch located in the refrigerant
discharge line and wired across the HPC
terminals on the UPM

• Low pressure switch located in the unit
refrigerant suction line and wired across
terminals LPC1 and LPC2 on the UPM.

UPM Board Dry Contacts are Normally Open
(NO)

• Water side freeze protection sensor, mounted
close to condensing water coil, monitors
refrigerant temperature between condensing
water coil and thermal expansion valve. If
temperature drops below or remains at freeze
limit trip for 30 seconds, the controller will
shut down the compressor and enter into a
soft lockout condition. The default freeze limit
trip is 30°F, however this can be changed to
15°F by cutting the R30 or Freeze1 resistor
located on top of DIP switch SW1. Refer to
Figure #6, item [3] for resistor location. (Refer
to Figure #7 for sensor location)

Figure # 7

If unit is employing a fresh water system (no
anti-freeze protection), it is extremely
important to have the Freeze1 R30 resistor
set to 30°F in order to shut down the unit at
the appropriate leaving water temperature
and protect your heat pump from freezing if
a freeze sensor is included.

• The condensate overflow protection sensor is
located in the drain pan of the unit and
connected to the ‘COND’ terminal on the UPM
board. (Figure #8)

Figure # 8

LM CS Series Heat Pump8 733 920 847 (2014/01) Subject to change without prior notice

UPM Board Factory Default Settings

TEMP

LOCKOUT

RESET

ALARM

TEST

30°F

2

Y

PULSE

NO

UPM DIP SWITCH DEFAULT POSITION

lockout 42

Electrical | 9LM CS Series Heat

• MALFUNCTION OUTPUT: Alarm output is

Normally Open (NO) dry contact.

If pulse is
selected the alarm output will be pulsed. The
fault output will depend on the dip switch
setting for "ALARM". If it is set to "CONST", a
constant signal will be produced to indicate a
fault has occurred and the unit requires
inspection to determine the type of fault. If it is
set to "PULSE", a pulse signal is produced and
a fault code is detected by a remote device
indicating the fault. See LED Fault Indication
below for blink code explanation. The remote
device must have a malfunction detection
capability when the UPM board is set to
"PULSE".

reset

alarm

test

RY

Cont pulse

yes no

The UPM Board includes the following features:

• ANTI-SHORT CYCLE TIMER:

break timer to prevent compressor short cycling.

5 minute delay on

• RANDOM START: Each controller has an unique

random start delay ranging from 270 to 300 seconds
on initial power up to reduce the chance of multiple
unit simultaneously starting at the same time after
power up or after a power interruption, thus
avoiding creating large electrical spike.

• LOW PRESSURE BYPASS TIMER: If the

compressor is running and the low pressure switch
opens, the controller will keep the compressor ON
for 120 seconds. If, after 120 seconds the low
pressure switch remains open, the controllers will
shut down the compressor and enter a soft lockout.
The compressor will not be energized until the low
pressure switch closes and the anti-short cycle time
delay expires. If the low pressure switch opens 2-4
times in 1 hour, the unit will enter a hard lockout. In
order to exit hard lockout power to the unit would
need to be reset.

• BROWNOUT/SURGE/POWER
INTERRUPTION PROTECTION:

protection in the UPM board will shut does the
compressor if the incoming power falls below 18
VAC. The compressor will remain OFF until the
voltage is above 18 VAC and ANTI-SHORT CYCLE
TIMER (300 seconds) times out. The unit will not go
into a hard lockout.

The brownout

If 24 VAC output is needed R must be wired to
ALR-COM terminal; 24 VAC will be available o
the ALR-OUT terminal when the unit is in the
alarm condition.

• TEST DIP SWITCH:

to reduce all time delays settings to 10 seconds
during troubleshooting or verification of unit
operation.

Operation of unit in test mode can lead to
accelerated wear and premature failure of
components. The "TEST" switch must be set
back to "NO" after troubleshooting/
servicing.

A test dip switch is provided

• FREEZE SENSOR: The default setting for the

freeze limit trip is 30°F (sensor number 1); however
this can be changed to 15°F by cutting the R30
resistor located on top of the DIP switch SW1.

default setting for the freeze limit trip is 30°F
(sensor number 1); however this can be
changed to 15°F by cutting the R24 resistor
located on top of the DIP switch SW1. Since
freeze sensor 2 is dedicated to monitor the
evaporator coil it is recommended to leave the
factory default setting on the board. The UPM
controller will constantly monitor the
refrigerant temperature with the sensor
mounted close to the condensing water coil
between the thermal expansion valve and
water coil. If temperature drops below or
remains at the freeze limit trip for 30 seconds,
the controller will shut the compressor down
and enter into a soft lockout condition. Both
the status LED and the Alarm contact will be
active. The LED will flash (three (3) times) the
code associated with this alarm condition. If
this alarm occurs 2 times (or 4 if Dip switch is

The

8 733 920 847 (2014/01)Revised 01-14

10 | Comfort Alert Module LM CS Series Heat Pump

set to 4) within an hour the UPM controller will
enter into a hard lockout condition. It will
constantly monitor the refrigerant temperature
with the sensor mounted close to the
evaporator between the thermal expansion
valve and evaporator coil as shown in Figure
#4. If temperature drops below or remains at
the freeze limit trip for 30 seconds, the
controller will shut the compressor down and
enter into a soft lockout condition. Both the
status LED and the Alarm contact will be
active. The LED will flash (three (6) times) the
code associated with this alarm condition. If
this alarm occurs 2 times (or 4 if Dip switch is
set to 4) within an hour the controller will enter
into a hard lockout condition.
Refer to page #10 for more information.

Freeze sensor will not guard against loss of
water. Flow switch is recommended to
prevent unit from running, if water flow is
lost or reduced.

• INTELLIGENT RESET: If a fault condition is
initiated, the 5 minute delay on break time
period is initiated and the unit will restart after
these delays expire. During this period the
fault LED will indicate the cause of the fault. If
the fault condition still exists or occurs 2 or 4
times (depending on 2 or 4 setting for Lockout
dip switch) before 60 minutes, the unit will go
into a hard lockout and requires a manual
lockout reset. A single condensate overflow
fault will cause the unit to go into a hard
lockout immediately, and will require a manual
lockout reset.

• LOCKOUT RESET: A hard lockout can be reset
by turning the unit thermostat off and then
back on when the “RESET” dip switch is set to
“Y” or by shutting off unit power at the circuit
breaker when the “RESET” dip switch is set to
“R”.

The blower motor will remain active during a
lockout condition.

COMFORT ALERT MODULE

The Comfort Alert diagnostics module (CADM) is a
breakthrough innovation for troubleshooting heat
pump system failures. (Figure #9)

Figure # 9

By monitoring and analyzing data from the
compressor and the thermostat demand, the
module can accurately detect the cause of
electrical and system related failures without any
sensors. A flashing LED indicator communicates
the ALERT code and guides the service technician
more quickly and accurately to the root cause of a
problem.

This module does not provide safety protection!
The Comfort Alert module is a monitoring device
and cannot shut down the compressor directly.

When an abnormal system condition occurs, the
Comfort Alert module displays the appropriate
ALERT and/or TRIP LED.

The yellow ALERT LED will flash a number of times
consecutively, pause and then repeat the process.

To identify a Flash Code number, count the
number of consecutive flashes.

• Every time the module powers up, the last
ALERT Flash Code that occurred prior to shut
down is displayed for one minute.

LM CS Series Heat Pump8 733 920 847 (2014/01) Subject to change without prior notice

Figure 10: Refrigerant Charge, Line Sizing and Capacity Multiplier Chart

Comfort Alert Module | 11LM CS Series Heat

SYSTEM
MODEL

LM024

LM036

LM048

LM060

LM070

Factory

R410A

Charge

(Oz)*

80

86

93

115

127

CAPACITY MULTIPLIER

Example 1:

Model LM036 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.

Refrigerant Line O.D. Size (Based on Equivalent Line Length)

25 FT. 35 FT. 45 FT. 50 FT. 75 FT

LIQ. SUC. LIQ. SUC. LIQ. SUC. LIQ. SUC. LIQ. SUC.

3/8 3/4 3/8 3/4 3/8 3/4 3/8 3/4 3/8 7/8

3/8 3/4 3/8 3/4 3/8 3/4 3/8 7/8 3/8 7/8

3/8 7/8 3/8 7/8 3/8 7/8 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 1-1/8

3/8 1-1/8 3/8 1-1/8 3/8 1-1/8 3/8 1-1/8 3/8 1-1/8

1.00 .995 0.990 0.990 0.980

Figure 11: Liquid Line Charge Per Linear Foot

Liquid Line Size, O.D.

Suct. Line

Riser Max.

3/4

3/4

7/8

7/8

7/8

Example 2:

Model LM060 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.

R410A oz per foot

1/4 5/16 3/8 1/2 5/8
.25 .44 .60 1.15 1.95

8 733 920 847 (2014/01)Revised 01-14