Carrier 50KQL-1PD manual Optional Controls, F. Electrical Requirements, G. Special Features

7.Optional Controls:

a.Unit-mounted ACO (automatic changeover) thermostat operating controls shall consist of temperature setting dial knob, push button switches for Stop, Fan only, Hi fan, Lo fan. Unit-mounted thermostats shall have a remote sensor for sensing the return-air temperature.

b.Units designed for connection to remote wall mounted thermostat shall be wired such that the operating controls are at the thermostat. The controller shall be provided with a low voltage field wiring terminal block. The con- trol scheme shall accommodate MCO or ACO heat pump thermostats with Y, G, and O outputs. An alternate controller shall be available from the factory to accommodate the Heat/Cool thermostats.

c.Motorized (2-way) water valves shall be factory installed and wired. The valve shall remain open when there is a cooling or heating demand and the compressor is running. The valve shall close when the compressor stops after satisfying the demand or due to lockout condition.

d.Fresh air dampers shall be motorized with a spring return. The damper shall open when Cooling or Heating mode selection is made from the unit-mounted switches. With a remote thermostat, the damper shall open any time the fan is in operation.

e.Night low limit thermostats shall include a unit-mounted thermostat sensing space tem- perature. Should the space temperature fall below the limit, the night low limit thermo- stat shall start the fan and compressor oper- ation in Heating mode.

f.Units with the unit-mounted thermostat shall include a 2-hour override function. The override switch shall be readily accessible. In override mode the unit operation shall be the same as in occupied mode. Override mode shall be terminated automatically at the end of a 2-hour period.

F.Electrical Requirements:

1.A control box shall be located within the unit compressor compartment and shall contain a 50 va transformer, 24-volt activated, 3-pole compressor contactor, terminal block for thermostat wiring and solid-state controller for complete unit operation. Electro-mechanical operation WILL NOT be accepted.

2.Units shall be nameplated for use with time- delay fuses or HACR circuit breakers.

3.Unit controls shall be 24-volt and provide heating or cooling as required by the remote thermostat.

G.Special Features:

1.Aquazone™ Thermostat Controls (for use with remote thermostat units):

a.Programmable multi-stage thermostat with 7-day clock, holiday scheduling, large backlit display and remote sensor capability.

b.Programmable 7-Day Light-Activated Ther- mostat offers occupied comfort settings with lights on, unoccupied energy savings with lights off.

c.Programmable 7-Day Flush-Mount Thermo- stat offers locking coverplate with tamper proof screws, flush to wall mount, dual point with adjustable deadband, O or B terminal, and optional remote sensor.

d.Programmable 5-Day Thermostat offers 2-stage heat, 2-stage cool, auto changeover, 5-minute built-in compressor protection, lock- ing cover included.

e.Non-programmable Thermostat with 2 heat stages, 2 cool stages, auto changeover, 5-minute built-in compressor protection, lock- ing cover included.

2.Aquazone System Control Panel:

The panel shall coordinate, monitor, and con- trol all WSHP units and ancillary equipment including cooling towers, boilers, and system pumps.

3.Fire-Rated Hose kits:

Hoses shall have a fixed MPT on one end and a swivel with an adapter on the other end. Hose kits shall be either stainless steel or galvanized.

4.Ball Valves (Brass Body):

Ball valves shall be for shutoff and balancing water flow. Valves shall be available with memory, memory stop, and pressure temperature ports.

5.Y Strainers (Bronze Body):

Strainers shall have “Y” type configuration with

abrass cap. Strainers shall have a maximum operating pressure rating of 450 psi. Strainer screen shall be made of stainless steel.

6.Solenoid Valves (Brass Body):

Valves shall provide slow operation for quiet system application.

7.Hose Kit Assemblies:

Hose kits shall include a ported ball valve with pressure temperature (P/T) plug ports, flexible stainless steel hose with swivel and nipple. Return hose includes a ball valve, preset mea- sure flow (gpm) with two P/T ports, flexible stainless steel hose with a swivel and nipple.

8.Remote Sensors:

Sensors for Aquazone flush-mount thermostats shall be available.

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