Sequence of Operation

LW Series Dehumidifiers

SEQUENCE OF OPERATION

Supply Blower

In default mode the supply blower is set to run continuously. The supply blower can also be set to Automatic mode at the controller. In Automatic mode the blower will run on a demand call for cooling, dehumidification or space heating. When set for Automatic operation the supply fan stops when conditions are satisfied based on the controller set points.

Dehumidification

When dehumidification is required, the compressor starts and the hot gas will be rejected to reheat condenser to provide free heating to the supply air. When the space cooling set point is reached the heat of rejection maybe shifted to the optional or customer supplied remote condenser.

Cooling

When cooling is needed the compressor starts and the hot gas will be rejected to the optional remote condenser.

Air Heating

During a call for dehumidification, the unit operates in reheat mode.

The field-installed and supplied auxiliary heater is activated by closing dry contactsH1/H2and/or a 0-10VDC control signal from the dehumidifier.

{One of the three following options must be selected based on the selection in ProjectAire.}

Exhaust and Outside Air (No Outside Air Provision)

An internal time schedule and two sets of dry contacts are available to control an exhaust fan and the external outdoor air damper by others.

·  During unoccupied times the contacts D1/D2 and E1/E2 are open.

·  During occupied times the contacts D1/D2 and E1/E2 are closed.

Exhaust and Outside Air (Outdoor Air with Duct Connection)

Two sets of dry contacts are available to control an exhaust fan (E1/E2) and the external outdoor air damper by others. (D1/D2).

·  During unoccupied times the D1/D2 contacts for control of an outside air intake damper (by others)are open.E1/E2contacts for control of an external exhaust fan( by others) are also open in unoccupied mode.The internal bypass damper opens to keep the systemairflow constant.

·  During occupied times the D1/D2 contacts for control of outside air intake damper(by others)areclosed.E1/E2 contacts for control of an external exhaust fan (by others) are also closed in occupied mode.The internal bypass damper closes to keep the system airflow constant.

Exhaust and Outside Air (Outdoor Air with Damper or Damper and Filter)

A set of dry contacts are available to control an exhaust fan (E1/E2).

·  During unoccupied times the E1/E2 contacts for control of an external exhaust fan (by others) is open. The outdoor air damper closes and the internal bypass damper opens to keep the system airflow constant.

·  During occupied times the E1/E2 contact for the control of an external exhaust fan (by others) are closed. The outdoor air damper opens and the internal bypass damper closes to keep the system airflow constant.

Sequence of Operation (LW) 201706