Catalogue

76 UNT-PRC001-EN
Mechanical Specifications
Motors
All motors are brushless DC (BLDC)/electronically commutated motors (ECM) factory-
programmed and run-tested in assembled units. The motor controller is mounted in a touch-safe
control box with a built-in integrated user interface and LED tachometer. If adjustments are needed,
motor parameters can be adjusted through momentary contact switches accessible without
factory service personnel on the motor control board.
Motors will soft-ramp between speeds to lessen the acoustics due to sudden speed changes.
Motors can be operated at three speeds or with a field-supplied variable speed controller. The
motor will choose the highest speed if there are simultaneous/conflicting speed requests.
All motors have integral thermal overload protection with a maximum ambient operating
temperature of 104°F and are permanently lubricated. Motors are capable of starting at 50 percent
of rated voltage and operating at 90 percent of rated voltage on all speed settings. Motors can
operate up to 10 percent over voltage.
Controls
Controls options are: fan speed switch, control interface, and Tracer ZN010, ZN510, ZN520, and
UC400. A variety of inputs and outputs are available for the control interface and Tracer controller
options. A disconnect switch (for non-electric heat units), fused transformer, contactor(s), and
terminal strip are provided with the control interface and Tracer controller options. For specifics on
Tracer ZN010, ZN510, ZN520, and UC400, please refer to “Controls,” p. 39.
Control Interface
The control interface is intended to be used with a field-supplied, low-voltage thermostat or
controller. The control box contains a relay board which includes a line voltage to 24-volt
transformer, quiet contactors (for electric heat units), and an optional disconnect switch. All end
devices are wired to a low-voltage terminal block and are run-tested, so the only a power
connection and thermostat connection is needed to commission the unit. Changeover sensors and
controls are provided whenever a change-over coil is selected. When N.O. valves are selected,
inverting relays are provided for use with standard thermostats.
Fan Speed Switch
The fan speed switch is available with or without the control interface option and is available as
wall-mount or unit-mount. Both the wall-mount and unit-mount FSS will employ low-voltage fan
switches. However, the low-voltage fan speed option will provide an interface to factory wiring,
including variable speed/high-medium-low (HML) control. The control box contains a line voltage
to 24-volt transformer, ECM motor controller, and an optional disconnect switch.
Coils
All water coils are proof-tested at 300 psig (air) and leak-tested at 100 psig (air under water).
Maximum main coil working pressure is 300 psig. Maximum entering water temperature is 200°F.
Tubes and u-bends are 3/8”OD copper. Fins are aluminum and are mechanically bonded to the
copper tubes. Coil stubouts are 5/8” OD copper tubing.
Reheat Coils
Reheat coils are available for use with both hot water and steam. Hot water maximum working
pressure is 300 psig, and the maximum entering water temperature is 200°F. The steam coil
maximum working pressure is 15 psig. The reheat coils are constructed of single circuit 5/8” copper
tubes with aluminum fins. Piping connections are expanded to accept standard copper tubing
5/8”OD.
Piping Packages
All piping packages are proof-tested at 300 psig (air) and leak tested at 100 psig (air under water).
The maximum working pressure of the interconnecting piping is 300 psig.
Options
UNT-PRC001-EN.book Page 76 Tuesday, May 8, 2012 10:54 AM