| Performance Data Electric
Heat Electric Heat
All UniTrane ®
fan-coils are available with electric heating coils.
Low vertical units have electric heat available only
on units with a two-row cooling coil.
Coil Construction and
Location
Electric heat coils are open wire
type with a nickel chrominum element design. All coils are located in the preheat position on the standard UniTrane
fan-coil design and in the reheat position on the low
vertical fan- coil units.
Power Supply
Units have single-point power since
the electric heating elements operate on line voltage. In addition, all control options are 24-volt, utilizing a factory- installed
transformer.
Control Type
Fan-coil units with electric heat are
controlled by either of the standard control options: the thermostat module or
terminal unit controller (TUC). Both controllers use
PWM (pulse-width modulation) outputs that calculate the electric heat output based on the capacity request and the electric heat
cycles per hour. For example, if the electric heat
cycles per hour is configured for six cycles (as Trane
recommends) the controller bases the output on or off time on six 10-minute periods. If the capacity request is 40%, the
controller controls the electric heat output on for
approximately four minutes each period.
Electric Heat Features
- All fan-coil units are UL approved.
- Units require only a single-point
electrical connection.
- All electric heating coils are
interlocked with the fan motor switch. Therefore,
electric heat operation is only possible when the fan is running.
- Each unit has a transformer, eliminating the need for field installation
of a step-down transformer.
- A unit mounted magnetic contactor(s)
is (are) supplied on all unit voltages. • A high temperature cutout with automatic reset de-energizes the electric heat
in the event of an overheat condition.
- When hydronic heating is active, a
high temperature switch will disable the electric heat.
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