York WR240, WR300 warranty Reheat Mode Sequence Of Operation, Unit Cutaway, “Normal” Mode

Models: WR240 WR300

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FIGURE 1: UNIT CUTAWAY

262292-YTG-B-0107

FIGURE 1: UNIT CUTAWAY

Electric Heat Operation - All electric heat models (factory installed only) are wired for a single power source and include a bank of nickel chromium elements mounted at the discharge of the supply air blower to provide a high velocity and uniform distribution of air across the heating elements. Every element is fully protected against excessive current and temperature by fuses and two thermal limit switches.

The power supply wiring can be routed into the control box through a threaded pipe connection in the base pan of the unit or through a knockout in the wiring panel on the front of the unit.

BAS Controls - York’s Magnum series units offer factory mounted BAS controls such as Novar, Honeywell, Johnson, and CPC.

REHEAT MODE SEQUENCE OF OPERATION

The reheat control board allows the user to select two different modes of operation via a jumper connection on the board. (See Figure 2.) Each mode is described below. Refer to Figures 2 - 4 when reading this section.

REHEAT MODE SEQUENCE OF OPERATION LOCATION OF VFD (Optional)

“NORMAL” MODE LOCATION OF VFD BYPASS (Optional)

“NORMAL” MODE

When the reheat control board (RCB) detects a need for dehumidification (24VAC) at "HUM" via the field supplied dehumidistat connected to RHTB-1 and RHTB-2 and there is not a call for cooling, it energizes the hot gas relay (HGR), which energizes the 3-way valve (SOL 3), the condenser coil valve (SOL 2), and de-energizes the reheat coil bleed valve (SOL 1). The Y1 signal is passed to the unit control board (UCB), which engages circuit # 1, resulting in circuit #1 reheat mode operation.

When the room thermostat calls for first stage cooling, with or without a call for dehumidification, the RCB senses a signal through "Y1", de-energizing the HGR, which de-energizes SOL 3 and SOL 2, and energizes SOL 1, engaging circuit # 1, resulting in circuit #1 cooling mode operation.

When the room thermostat calls for second stage cooling, the RCB senses a signal through "Y1" & "Y2" and engages circuit #1 and circuit #2 in the cooling mode.

Indoor blower operation is initiated upon a call for first stage cooling, second stage cooling or dehumidification.

Unitary Products Group

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York WR240, WR300 warranty Reheat Mode Sequence Of Operation, Unit Cutaway, “Normal” Mode

FAQ

What are the electric heat models factory installed with?

All electric heat models factory installed are wired for a single power source and include a bank of nickel chromium elements.

What are the BAS controls offered by York's Magnum series units?

York's Magnum series units offer factory mounted BAS controls such as Novar, Honeywell, Johnson, and CPC.

What are the two different modes of operation that the reheat control board allows?

The reheat control board allows the user to select two different modes of operation: normal mode and [reheat mode].