Water Coil; Condensate Pan; Electric Heater - Size 1.6 - Resistance Heater Type; Electric Heater - Size 2.6 And 4.7 - Shielded Heater With Spiral Fins - Carrier 42BJ ULTRA Selection Manual

6.3 - Water coil

The water coil has aluminium fins which are expansion-bonded.
Water inlet and outlet connections are threaded 1/2" or 3/8" gas
(size 2.6). Air purge valves are stan±dard. The coil is integral
with the drain pan and coil access door to simplify removal for
service.
Coils available are for two-pipe systems with changeover or use
with electric heater and for four-pipe systems.
6.4 - Aluminium condensate pan
The main pan is below the coil with an auxiliary below the
valves. The monobloc construction prevents leaks. The coil is
on the suction side of the fan to facilitate drainage, and conden-
sate is drained through an opening at the base of the coil pro-
tection plate.
The auxiliary pan is insulated with 4 mm foam. The drain stub
itself has an external diameter of 16 mm.
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6.5 - Electric heater - size 1.6
Electric resistance heater type
• Specification: 230 V (±10%) - 1 ph - 50 Hz
• Capacity per heater: size 1.6 - 1000 W +5%/-10%)
• The heater is equipped with two safety devices:
a) An automatically controlled integrated safety thermostat
with a trigger temperature of 75°C.
When the trigger temperature is reached, a resistance heater
is automatically energised and prevents automatic resetting,
if the system is energised, but has insufficient air flow.
Reset is achieved by suppressing the supply voltage of the
electric heater. The safety thermostat protects the unit from
overheating, generally the result of electricity passing
through the heater when there is insufficient air flow.
b) A thermal fuse tripping at 150°C.
NOTE: The minimum discharge air flow of 64 l/s (230 m 3 /h)
is required to avoid damage to the electric heaters.
CAUTION: It is vital to disconnect the 42BJ from the general
power supply before working on the electric heater.
6.6 - Shielded electric heater - sizes 2.6 and 4.7
Shielded heater type with spiral fins
This is a shielded electric heater with spiral fins. It has two
stages, each of 800 W (+5%; -10%) wired in parallel. The elec-
tric heaters are connected within an IP407 galvanised sheet
steel casing which is fitted with a packing gland to admit the
power supply cable.
The heater unit is fitted with a manually reset safety thermo-
stat. This normally closed contact is triggered by a rise in tem-
perature to 112°C (+0; -16).
The safety thermostat protects the unit from overheating, gene-
rally the result of electricity passing through the heater when
there is insufficient air flow. The thermostat can be reset
without dismantling the unit. Simply remove the protective
cover from the terminal box (casing) on the heater and press the
small plastic rod located in the middle of the thermostat.
However, if the safety thermostat is triggered, it is essential to
find and rectify the cause before resetting.