Unit installation

IM 526 / Page 15
New MicroTech 2000 WSHP Controller Unit
The MicroTech 2000 WSHP unit controller is a prepro-
grammed, pretested microprocessor which:
● Controls unit heating and cooling functions in response
to a wall mounted comfort sensor.
● Monitors safety controls in each heat pump and
responds accordingly.
● Monitors discharge air temperature and leaving water
temperature at each heat pump.
● Provides fan, reversing valve, and compressor
operation.
● Provides control outputs for boilerless system electric
heat, motorized valves, fresh air damper, and other aux-
iliary equipment.
● Provides operation status of all vital unit functions.
● Provides optional night setback override for tenant
comfort.
The MicroTech 2000 WSHP unit controller supports a
minimum of 6 analog inputs, 4 digital inputs and 5 digital
outputs. All input and output connections to the controller
are made using Insulation Displacement Connectors (IDC).
The controller can operate a unit as either a stand-alone
device (for start-up, etc.) using factory programmed set-
points (see table below), or preferably, as part of the
MicroTech Network System through a MicroTech
Communications Gateway (MCG). On a call for constant fan
operation, the fan relay is energized. On a call for cooling,
the fan is energized (if not already on) and after a time delay
the compressor contactor is energized. On a call for heat-
ing, the fan is energized (if not already on) along with the
reversing valve and after a time delay the compressor con-
tactor is energized.
Standard lockout circuitry causes compressor lockout if
any one of its safety switches opens. In addition, when a
low temperature fault occurs the unit will run in the cooling
mode for 60 seconds to defrost the water to refrigerant heat
exchanger coil. If the condensate sensor detects a filled
drain pan, the compressor operation will be suspended only
in the cooling mode. The unit can be reset by either dis-
connecting power at the disconnect, feeding power to the
unit or by use of the Monitor™* program through the
MicroTech Network System. The unit does not have to be
reset on a condensate overflow detection.
A single onboard LED gives indication of the unit status
in relation to the following:
LED on — Occupied
LED mostly off — Unoccupied
LED mostly on — Unoccupied override
LED flashing — Fault
If the unit controller has not been assigned a logical
address, the intensity of the LED is low. If a logical address
has been assigned, the LED intensity is high.
Additional status and details are available by use of the
Monitor™ program and the MicroTech Network system
either by direct connection using a portable IBM-compati-
ble computer or through the system computer.
The amount of user control without the use of the net-
work is dependent on the type of comfort sensor used with
the unit. The room temperature sensor is currently available
in the following configurations:
● With LED indication and tenant override
● With LED indication, tenant override and setpoint differ-
ential adjustment
The LED display indicates the same conditions that the
onboard LED does. The tenant override switch allows the
tenant to switch from an unoccupied to an occupied com-
fort setpoint for a preprogrammed period of time. The ten-
ant setpoint differential adjustment allows heating and cool-
ing setpoint differentials to be modified by the tenant.
*The Monitor™ program is sold as part of the MicroTech
Network System.
This device complies with part 15 of the FCC Rules.
Operation is subject to the following two conditions:
1. This device must not cause harmful interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation.
DESCRIPTION FACTORY PROGRAMMED SETPOINT ADJUSTABILITY RANGE
Occupied Heating Setpoint 70°F (21°C) 35°-120°F (1.7°-49°C) ➀➄
Occupied Cooling Setpoint 74°F (23°C) 35°-120°F (1.7°-49°C) ➃➄
Fan - Occupied On On, Cycle, Heat, Cycle/Cool On
Unoccupied Heating Setpoint 60°F (16°C) 35°-120°F (1.7°-49°C) ➀
Unoccupied Cooling Setpoint 85°F (29°C) 35°-120°F (1.7°-49°C) ➂
Fan - Unoccupied Cycle On, Cycle
Tenant Override - 1st press 1:00 Off, 0:30 - 8:00
Tenant Override - 2nd press Off Off, 0:30 - 8:00
Differential 2°F (1.2°C) 1°-10°F (0.6°-5.6°C) ➄
Auto / Manual Auto Manual (occupied, unoccupied, fan only, off)
Next Filter Change (hours) 600 100 - 5000
Clock Schedule 1 Up to 32
Load Shed Start Level Off Off, 1 to 7
Tenant Setpoint Adjustment Off (0°F, 0°C) Off, On (3°F, 1.7°C)
Low Temperature Warning 55°F (13°C) 35°F (1.7°C) — high not used
High Temperature Warning 95°F (35°C) Low not used — 120°F (49°C)
➀ Unoccupied heating setpoint cannot exceed high warning setpoint.
➁ Occupied heating setpoint cannot exceed unoccupied heating setpoint.
➂ Unoccupied cooling setpoint cannot be lower than low warning setpoint.
➃ Occupied cooling setpoint cannot be lower than unoccupied cooling setpoint.
➄ Occupied heating and occupied cooling setpoints must differ by at least the differential.
NOTICE