Electric Heater Package Option; Water Quality - Bosch EP Series Installation And Maintenance Manual

EP Series

ELECTRIC HEATER PACKAGE OPTION

WARNING: The HP series heater
package requires its own electrical
service separate from the heat pump's
power supply. DO NOT attempt to wire
the package into the same circuit as the
heat pump.
Factory installed internal electric heater packages
are available for EP Series units. Two power
supplies are required when heater packages are
utilized. The power supply for the heater package
(located in the electric heater package control
box) provides power for the heater elements, the
blower motor and the control circuit for the unit.
The power supply for the unit provides power for
the compressor. This allows the electric heaters to
continue to operate along with the blower motor in
the case of unit compressor and/or compressor
power supply failure.
Each EP Series model has a number of heater sizes
available. Refer to Figure #18 for heater package
compatibility with specific EP series units, model
nomenclatures and electrical data.
Electric Heather compatibility
Model 5 kW

EP018
 
EP024
 
EP030
 
EP036
 
EP042
 
EP048
 
EP060
Figure # 18
NOTE: If heat recovery unit is installed in an
area where freezing may occur, the unit
must be drained during winter months to
prevent heat exchanger damage. Heat
exchanger ruptures that occur due to
freezing will void the heat recovery package
warranty along with the heat pump
warranty.
EP Series
10 kW 15 kW 20 kW


 
 
Electric Heater Package Option | 15

WATER QUALITY

NOTE: Failure to insure proper water quality
and flow rates can shorten the life of the
heat pump and potentially void the unit
warranty.
Maintaining proper water quality is important for
insuring a long and trouble free service life for an
LV series heat pump.
For closed loop and boiler/tower systems water
chemistry can be checked and easily maintained to
insure that corrosive elements, dissolved oxygen
and pH levels are kept in check. It is important to
insure that any additive, antifreeze or corrosion
inhibitor that is added to the water loop is
compliant with all applicable laws and regulations
and is compatible with copper, brass and bronze
alloys. Insure that all recommended safety
precautions are followed when handling or adding
chemicals to the water loop.
For open loop systems, water quality is very
important. Refer to Quality Table on page# 6
shows acceptable ranges for a variety of water
quality factors. The three main concerns in open
loop installations are scaling, corrosion and
fouling.
In installations with hard water, scaling due to a
buildup of carbonates on the heat exchanger wall
can gradually degrade the heat pump performance
over time. Heat pumps that are affected by scaling
may exhibit low suction pressures in heating and
high head pressures in cooling with a gradual loss
of capacity and efficiency. Scaled heat exchangers
can be cleaned by a qualified technician but care
should be taken to avoid scaling in the first place.
To limit scaling, water flow rates should be kept at
3 gallons/minute per nominal cooling ton (a 10°F
temperature rise in cooling) and care should be
taken to avoid air in the water lines from suction
side leaks. Cupro-nickel coils are generally
recommended.
In installations with high hydrogen sulfide, chlorine
or ammonia, corrosion is a potential problem. In
these installations a cupro-nickel heat exchanger is
recommended along with maintaining proper flow
and keeping air out of the system. If water quality
is outside of the values in water quality table, then
a closed loop is recommended.
Fouling due to iron bacteria can also pose
problems in some open loop installations. Iron
bacteria fouling can quickly degrade system
performance and plug heat exchangers.
Air in the water system will greatly accelerate the
fouling or corrosion process.
8733953041 (2019/01)