Johnson Controls York VCH 20A, Technical Information

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Internal Electric Heaters for VIR 25A to
90A
The internal electric heaters are designed to provide backup
or complementary heat in the VIR units. On and off cycles
are governed by the air conditioning equipment control sys-
tem. They are to be fitted on to the internal supports of the
indoor unit.
Technical specifications
These internal electric heaters include the following com-
ponents:
- Galvanised sheet casing and supports.
- Exposed nickel-chrome wire electric resistances mounted
on steatite supports.
- Control board of auxiliary heater A3 (A3 and A4 in 2 stages).
- Power supply contactor with a 24 V coil.
- Two thermal protectors located at the top of the heater. The
first, with automatic reset, disconnects the heater when a
temperature of 77° C is reached.
The second, accessible from the outside the unit and with
manual reset, disconnects the heater when a temperature
of 138° C is reached.
The 2-stage heaters are quipped with four thermal protec-
tors, two per stage.
- Interlocking with the heat relay of the indoor fan. The unit
control system does not allow the heater to be in operation
in the case of a failure of the indoor fan heat relay.
- Quick connector for interconnecting the unit control panel
and the heater (length 20 m). There is a kit for 50 m con-
nections (option).
Assembly and general dimensions mm.
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