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12 - CARRIER ELECTROMECHANICAL CONTROLLER
12.1 - Description
The ULTRA may be fitted with an electromechanical control-
ler developed and tested by Carrier in our research and deve-
lopment laboratories.
If this option is taken, each ULTRA then has a water flow
control valve or valves of the “on/off” type, flexible water
pipes to simplify the connection of units to the primary hot
and/or chilled water circuits, and in appropriate cases a power
relay for controlling the electric heater.
This option also includes a male-female quick connect termi-
nal block for connecting the various cables that come from the
three speed fan motor, the valve actuators, the electric heater
power relay and, if appropriate, from the heating/cooling
changeover configuration switch for ULTRAs fitted with a
single “hot or cold” coil.
The male-female quick connect terminal block and the electric
heater power relay are mounted on DIN rail and protected by
an ABS cover.
The DIN rail is made large enough to accept a bipolar discon-
necting switch and integral fuse holder (please contact your
Carrier representative).
The quick connect terminal block and flexible water pipes will
be appreciated when servicing work is being carried out, since
they enable service times to be significantly reduced.
Replacing or moving a unit becomes a simple matter.
A wall-mounted room thermostat can be supplied with the
ULTRA as an accessory. This thermostat will be connected
directly to the female side of the quick connect terminal block
(see section describing room thermostats).
12.2 - The various ULTRA configurations available
Each ULTRA can be fitted with one or two on/off valves, two
or three ports and flexible water pipes, depending how the hea-
ter is configured.
a) The ULTRA is fitted with a 5-row cooling coil (2 pipes).
Operates in cooling mode only.
This option includes a 2-port on/off valve and two insulated
flexible water pipes.
b) The ULTRA is fitted with a 5-row cooling or heating coil
(2 pipes with changeover).
Operates in cooling or heating mode. This application is of the
heat pump type.
This option includes a 3-port on/off valve, a heating/cooling
changeover switch and two insulated flexible water pipes.
c) The ULTRA is fitted with a 5 row cooling coil and 1 row
heating coil (4 pipes).
Operates in cooling and heating mode in sequence.
This option includes 2 valves, 2 on/off ports and 4 flexible
water pipes, 2 of which are insulated and 2 uninsulated.
d) The ULTRA is fitted with a 5 row cooling coil and an
electric heater (2 pipes and 2 wires).
Operates in cooling mode or heating mode with electric heater
in sequence.
This option includes a 2-port on/off valve, 2 insulated flexible
water pipes and 1 power relay for controlling the electric hea-
ter.
12.3 - Technical specification for the heating/cooling
changeover switch
The heating/cooling changeover switch is designed to be in-
stalled straight onto the couplings of the 3-port valves on the
ULTRA. It detects temperature changes in the fluid circulating
in the primary water circuit. A changeover switch operates
according to the water temperature in accordance with the dia-
gram below.
WIRE LENGTH:
1000 mm