Water Treatment; Service; General; Coils - Carrier 42DH 06 Installation, Start-Up And Service Instructions Manual

Electric Heater
Amps
kW Three Phase
(1, 2 or 3 stage)
208V 240V 480V 1 stg 2 stg 1 stg 2 stg 1 stg 2 stg 1 stg 2 stg 3 stg 1 stg 2 stg 3 stg 1 stg 2 stg 3 stg 1 stg 2 stg 3 stg
1.0 2.8 2.4 1.2
1.5 4.2 3.6 1.8
2.0 5.6 4.8 2.4
2.5 6.9 6.0 3.0
3.0 8.3 7.2 3.6
3.5 9.7 8.4 4.2
4.0 11.1 9.6 4.8
4.5 12.5 10.8 5.4
5.0 13.9 12.0 6.0
6.0 16.7 14.4 7.2
7.0 19.4 16.8 8.4
8.0 22.2 19.2 9.6
9.9 27.5 23.8 11.9
12.0 33.3 28.9 14.4
14.0 38.9 33.7 16.8
15.0 41.6 36.1 18.0
16.0 — 38.5 19.2
18.0 — — 21.7
19.9 — — 23.9
25.0 — — 30.1
30.0 — — 36.1
LEGEND
X — Available Option
– — Not Available

Water Treatment

Proper water treatment is a specialized industry. Carrier recom-
mends consulting a water treatment expert to analyze water for
compliance with water quality parameters listed below, and to
recommend an appropriate water treatment regimen. Water
treatment experts are able to recommend typical additives such
as rust inhibitors, scaling preventative, antimicrobial growth
agents, or algae preventatives. Anti-freeze solutions may also
be used to lower the freezing point.
Carrier water coil tubes and headers are constructed of cop-
per. Multiple brass alloys may be present in the valve pack-
age. It is the user's responsibility to ensure tube and piping
materials furnished by Carrier are compatible with treated
water. See Table 8.
Failure to provide proper water quality may affect the fan coil
units' warranty.
Table 8 — Water Quality Parameters
WATER CONTAINING
Sulphate
pH
Chlorides
Nitrate
Iron
Ammonia
Manganese
Dissolved Solids
CaCO3 Hardness
CaCO3 Alkalinity
Particulate Quantity
Particulate Size
Table 7 — Three Phase Electric Heater Availability
06 08 10
X — X — —
X — X — X
X — X — X
X — X — X
X — X — X
X — X — X
X X X X X
X X X X X
X X X X X
X X X X X
— — X X X
— — X X X
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REQUIRED CONCENTRATION
Less than 200 ppm
7.0-8.5
Less than 200 ppm
Less than 100 ppm
Less than 4.5 mg/l
Less than 2.0 mg/l
Less than 0.1 mg/l
Less than 1000 mg/l
300-500 ppm
300-500 ppm
Less than 10 ppm
800 micron max
UNIT SIZE (Heater Stages)
12
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— X — — —
— X — — —
— X — — X
— X — — X
— X — — X
X X X — X
X X X — X
X X X — X
X X X — X
X X X — X
X X X — X
X X X — X
— X X X X
— — — — X
— — — — X
— — — — X
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NOTES:
1. Electric Heating Capacities BTUh)=Heater kW x 3413.
2. Electric Heater Amp. for 3-phase Power = (Heater kW x 1000)/
(Applied Voltage x 1.73).

General

Each unit has an individual operating environment and condi-
tions that dictate its maintenance schedule. A formal schedule
of regular maintenance and an individual unit log should be es-
tablished and maintained. This will achieve maximum perfor-
mance and preserve the service life of each unit.
Observe and adhere to all safety precautions contained in the
preface of this manual during all service and maintenance
operations.
For more detailed information of service operations consult a
Carrier Sales Representative or the factory.

Coils

Coils should be cleaned by brushing the entering air face be-
tween fins with a stiff brush. Brushing should be followed by
cleaning with a vacuum cleaner. If a compressed air source is
available, the coil may also be cleaned by blowing air through
the coil fins from the leaving air face. This should again be fol-
lowed by vacuuming. Units equipped with regularly replaced
air filters will require less frequent coil cleaning.

Electric Resistance Heater Assembly

Electric resistance heaters typically require no scheduled main-
tenance when unit air filters are changed properly. The opera-
tion and service life may be affected by other conditions and
equipment in the system. The two most important operating
conditions for an electric heater are proper airflow and proper
supply voltage. High supply voltage and/or poorly distributed
or insufficient airflow over the element will result in element
overheating and possible limit switch openings. See Tables 6
and 7.
This condition may result in the heater cycling on the high lim-
it thermal cutout. Open-strip heaters have an automatic reset
switch and high-limit thermal switch as a backup. Automatic
reset limit switches reset after the heater has cooled down.
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SERVICE

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