Armstrong World Industries 243, 302, 242 Specifications, Magic-Pak HW/HWC, FAN ON Low Voltage

SPECIFICATIONS

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3.The unit continues cooling as long as both Y and G are energized. When the cooling call is satisfied, the circuit between Y, G and R is interrupted. The contactor immediately opens, interrupting power to the compressor and the outdoor cooling fan.

4.With the low voltage signal to terminal G on the blower control board interrupted, the board starts a countdown to blower “off”. After approximately 90 seconds, the cooling speed relay opens and the circulating air blower shuts down (see note at the end of this section).

Low Voltage

1.On a call for cooling, the thermostat closes the circuit between R and terminals G and Y.

2.The 24-volt signal energizes terminal G on the blower control board, starting the fan “on” timer. After approximately 15 seconds, the relay closes (see note at the end of this section). This sends line voltage to the COOLING speed terminal on the board, which starts the circulating air blower.

3.The signal from Y energizes the contactor, starting the compressor and the outdoor cooling fan.

4.When the cooling call is satisfied, both G and Y de- energize. The contactor opens immediately, causing the compressor and the outdoor cooling fan to stop.

5.The circulating air blower stops approximately 90 seconds after the G terminal on the blower control board de-energizes (see note at the end of this section).

FAN ON

Low Voltage

1.When the switch on the thermostat is moved to the “FAN ON” position, a 24-volt signal is sent to the G terminal on the blower control board.

2.With G energized, the blower control board starts a countdown to fan “on”. Approximately 15 seconds later (or immediately - see note at the end of this section), the fan starts.

3.The blower control board closes a relay on the board, sending line voltage to the terminal on the board marked COOL. This starts the circulating air blower.

4.When the switch at the thermostat is moved to the “OFF” position, the 24-volt signal to the blower control board is interrupted. With no signal at the

G terminal, the blower control board starts a countdown to fan “off”. Approximately 90 seconds later, a relay on the blower control board opens (see note at the end of this section). This interrupts the power to and stops the circulating air blower.

Magic-Pak: HW/HWC

Note: Heatcraft blower control boards have a G “on” delay of 15 seconds and an “off” delay of 90 seconds. Tridelta blower control boards have no “on” time delay and a 60 -130 second “off” delay.

SRM-HW/HWC

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