2. Insert a test line with tee between the pressure switch and blower. One piece of the tubing connects the pressure switch to the fitting at the back side of the induced draft blower housing. Connect the tee to the manometer as shown in Figure 5-20. Note: Always keep the pressure switch in the circuit when measuring. Switches incorporate internal bleeds to keep moisture out of the pressure switch line. 3. Using Table 5-4 on page 5-22 and the formula provided above, calculate the close value for

2. The contactor closes immediately upon receiving the 24-volt signal, causing the compressor and condenser fan motors to start. 3. The 24-volt signal is also sent to pin 1 of the 5-pin thermostat harness, initiating a 5-second circulating air blower “on” delay. 4. After the 5-second delay, the ignition control energizes the cooling speed relay and the circulating air blower starts. 5. When the cooling call is satisfied, the thermostat interrupts the R, Y and G circuit. The contactor de-energize

Disclaimer This manual presents information and guidelines for proper installation, adjustment, operation and maintenance of Armstrong Magic-Pak HW/HWC Thru-the-Wall units. Read this manual before attempting assembly, installation, start-up, adjustment or operation of the unit. If you have any questions about the operation of the unit or a particular safety device, call or write Arm- strong Air Conditioning Inc., 421 Monroe Street, Bellevue, Ohio USA 44811. Telephone: 419483- 4840 Fax: 419-483-3

2. When W is energized, a 24-volt signal is also sent to the W terminal on the blower control board. Approximately 60 seconds after W terminal energizes, the timer on the blower control board closes the heat speed relay on the board. This sends line voltage to the H terminal on the blower control board, which starts the circulating air blower. 3. The induced draft blower and the circulating air blower continue to operate as long as W is energized. 4. When W de-energizes, a relay in the ignition

To see simplified and detailed sequences of operation for the HWC122, 182, 242, 302 models equipped with the Fenwal Triton 2461D DSI Ignition Control, refer to pages 2-17 to 2-20. To see simplified and detailed sequences of operation for the HWC122, 182, 242, 302 models equipped with the Fenwal 05-29 Ignition Control, refer to pages 2-27 to 2-30. SEQUENCE OF OPERATIONS SRM-HW/HWC 2/99 Service Reference Manual UNIT TEAR DOWN Section 3 - Unit Tear Down Heating Section Heat Exchanger Removal ......

64HWC302-1A First find Model #. ------------------------------------------------> 64HWC302-1(*) Then match Service Level for desired part.----------------> REC STOCKING PART SERVICE LEVEL = * 26HWC122-1(*) 38HWC122-1(*) 38HWC182-1(*) 51HWC182-1(*) 64HWC182-1(*) 38HWC242-1(*) 51HWC242-1(*) 64HWC242-1(*) 51HWC302-1(*) 64HWC302-1(*) REF PART # PART DESCRIPTION 250 38982B001 COIL OUTDOOR A 1 1 250 38983B001 COIL OUTDOOR A 1 1 1 1 1 1 250 38984B001 COIL OUTDOOR A 1 1 255 35658B001 CONTACTOR A 1 1 1 1

38HWC242A-11A First find Model #. --------------------------------------------------------------> 38HWC242A-11(*) Then match Service Level for desired part. ------------------------------> REC STOCKING PART SERVICE LEVEL = * 38HWC182A-11(*) 38HWC242A-11(*) REF PART # PART DESCRIPTION 1 39370B001 TRANSFORMER + A-B 1 1 5 39029B001 CONTROL-BLOWER CENTER + A-B 1 1 7 43108-001 VALVE-GAS + A-B 1 1 11 42074-002 MANIFOLD A-B 1 1 13 39030B004 ORIFICE #53 NATURAL GAS A-B 4 4 20 41957-001 ELECTRODE + A-B 1

For natural gas installations, check the burner rate by observing the gas meter (making sure that all other gas appliances are turned off). The test hand on the meter should be timed for at least one revolution. Note the number of seconds for one revolution. BTU/HR Cubic Feet Per Revolution Heating = X 3600 X INPUT # Seconds Per Revolution Value Adjustments - Cooling Section (HWC models) No adjustments are required or should be attempted regarding any of the components of the cooling chassis. Th