+ Mhpul; Mcu+ / Mcup / Dcue; Outdoor Unit Wiring; 3 Ph Compressor Rotation - Marstair CC 875 Technical Manual

CC875L

+ MHPUL

CC 875L + MHPUL
JMODE
or
CN-MODE
OK
CC 875L

MCU+ / MCUP / DCUE

1

OUTDOOR UNIT WIRING

Cable entry for the outdoor unit electrics is through the cabinet to a terminal block.
Outdoor unit fan motors have a single speed and are ready for use at all outdoor temperatures.
MCU condensing units are suitable for temperate climates. If continuous running is expected at ambient temperatures
of 15°C or lower, a head pressure control kit is recommended.
MCU+, MHPUE, DCUE and DHPUE fan motors are supplied wired via a head pressure controller to give maximum
control.
Ensure all connections are secure and that both units are earthed.

3 Ph COMPRESSOR ROTATION

On 3 Ph units it is possible for the compressor to run backwards. This becomes obvious on start up: the compressor will
not develop a normal running pressure differential and the top will not become warm. It may be excessively noisy. To
reverse the rotation, switch off the mains power, identify the phase supplying the indoor unit, and exchange the other two
incoming supply phases.
DATA PLATES
Because of the ability to mix-match indoor and outdoor units, the data plate only gives information on outdoor units. To
obtain the system details, input power and currents from indoor and outdoor units should be added together. Data plates
show basic units with electric heater kit loads shown separately.
FIRE LINK
Electromechanical models In order to automatically switch off the fan in the event of a fire, fit an external switch (240V,
3A, closed to run, volt free contact) between terminal block terminal 2 and the Marstair remote control thermostat terminal
2 ( L). This switch should be operated by the building's fire alarm or BMS system. See page 38
Electronic models: 'L' units: see page 39; 'E' units see page 40.
Tel: 01823 665660
Heronhill - for all your Marstair requirements
2
1
3
2
+ MCU+
CC 875L
+ MCUP
+ DCUE
JMODE JMODE
or
CN-MODE
CN-MODE
=
☺
www.heronhill.co.uk
☺
3
+ MCU+
CC 875L
+ MCUP
+ DCUE
☺
or
RLY1
3.15A
☺
J MODE
500m A
22
S S
=
☺
4
VANE
RLY8
Fax: 01823 665807