Question about Heating & Cooling
Hi, this service manual has the defrost control diagram you will need. the diagram is on page 17. i will post the link to the manual below.
CLICK HERE FOR THE LENNOX HP26 SERIES.
Posted on May 13, 2009
NOTE: All wiring must be in accordance with the National Electrical Code, latest edition, and all local electrical codes. 1. Disconnect electrical power from both indoor and outdoor units. 2. Remove control panel access cover. 3. Disconnect thermostat wires at low voltage control box. 4. Remove the unit’s eight thermostat connection wires from the low voltage control box. Remove and retain grommets as necessary. 5. Remove and retain three screws that secure the existing control to the control box. 6. Using the original screws, attach the new control to the control box. In most models, the control box will have three holes that can be used to mount the control. The lower left mounting hole for the old control will also be used as the lower left mounting hole for the new control. If necessary, drill 7/64” holes to provide at least three mounting screws for the control board. The control should be oriented so the TEST pins are at the top and the low voltage connections are on the left. 7. Connect the wire harness to the new control terminals as 8. Remove the yellow, black, and gray wires from the contactor coil terminals. 9. Connect the black wire of the new control harness to one of the contactor coil terminals. This black wire is one of the two wires connected to the “C” terminal of the new control. 10. Connect the yellow and gray wires of the new control harness to the other contactor coil terminal. 11. Route the gray wire from the contactor coil terminal to the low voltage control box. 12. Route the stripped ends of the thermostat connection wires of the new control harness to the low voltage control box. 13. Insert the gray wire and the stripped thermostat connection wires into the low voltage control box using the original grommets. 14. Move the component wires from the old control to the new control as shown in the following table. 15. Neatly bundle and secure the wires using a tie wrap. 16. Set the proper demand defrost “curve” using the shunt jumper in the upper left corner of the control. See Figure 1. The position of the jumper must correspond with the control being replaced. Table 2 shows the proper jumper pin positions for the various controls that might be replaced. 17. Install new wiring diagram. 18. Connect thermostat wires using field-supplied wire nuts. 19. Install control panel access cover. 20. Reconnect power to units. 21. Verify proper operation of unit.
Posted on May 12, 2009
click the link directly.
A vapor compression air conditioning system including defrost control valve means between the compressor outlet and the evaporator in bypass relationship to the condenser and expansion valve for supplying hot refrigerant directly to the evaporator for defrosting in response to a predetermined low temperature of refrigerant in the evaporator which corresponds to frost accumulation. The control valve includes a piston reciprocal in a housing and having one end of the piston exposed to the compressor outlet pressure and the second end exposed to a refrigerant pressure within a variable volume control chamber between the piston and the housing. A small diameter bleed port extending through the piston equalizes the pressure forces acting on the ends of the piston to normally maintain the piston in a closed position. When a bimetal spring in an adjacent enclosure senses a low refrigerant temperature which corresponds to frost accumulation on the evaporator, a passage between the control chamber and the enclosure is opened for rapidly reducing pressure in the control chamber and causing the piston to move to its open position in which hot refrigerant is directed to the evaporator.
An air conditioning system comprising: an evaporator for cooling air in a passenger compartment; a compressor for pressurizing refrigerant discharged from said evaporator; a condenser for cooling refrigerant discharged from said compressor; valve means for expanding refrigerant discharged from said condenser to a low pressure condition prior to its introduction into said evaporator; a defrost control valve assembly fluidly connected between said compressor and said evaporator and opened in response to a predetermined evaporator refrigerant temperature to direct hot refrigerant from said compressor directly into said evaporator for defrosting; said defrost control valve including a housing with a cylinder and a piston valve within said cylinder reciprocal between closed and open positions; one end of said piston valve being exposed to refrigerant pressure from said compressor outlet which exerts an opening force upon said piston valve; the other end of said piston valve forming a variable volume control chamber with said housing; said piston having a small diameter bleed port extending between said ends to said control chamber to transmit refrigerant pressure from the compressor outlet to said control chamber thus equalizing the pressure forces acting on the ends of the piston which normally maintains said piston in its closed position; said housing forming an enclosure connected to said control chamber by a passage and having an inlet and an outlet fluidly connected respectively to said evaporator and the inlet of said compressor; valve means for blocking said passage when in a closed position; bimetal spring means within said enclosure and connected to said valve member for moving said valve member into an open position in response to a predetermined evaporator refrigerant temperature corresponding to frost accumulation on said evaporator whereby said open passage decreases refrigerant pressure in said control chamber to permit a pressure force on said first end of said piston to move it into an open position permitting hot refrigerant to pass directly to said evaporator for defrosting.
Posted on May 11, 2009
Here are two links to the Lennox service bulletins.This should be a fairly straight forward replacement,this is a Lennox upgrade,all connections on the old unit should be marked on the board and correspond with the new unit.Dissconnect the power to the unit,write down all connections to the old board and the color of the wires before dissconnecting them,and then connect to the corresponding connections of the new board of new board,note that all the connections on the new board are named the same,be sure not to mix the incoming power leads.
Old part 68J8401
You will need Acrobat to open the second link.It also has instructions regarding the setup of the delay that is on the new board.
Posted on May 11, 2009
Please check these Installation instructions which will tell you how to connect a defrost control to air condition.
Please do accept the solution and revert for further assistance.
Posted on May 11, 2009
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Sep 28, 2016 | Refrigerators
Oct 17, 2012 | Refrigerators
Apr 19, 2011 | Kenmore 54739 Side by Side Refrigerator
Mar 11, 2010 | Refrigerators
Dec 30, 2009 | Kenmore Refrigerators
Aug 16, 2009 | Refrigerators
Jul 06, 2009 | GE (PSS26MSRSS) Side by Side Refrigerator
Jun 18, 2009 | GE GSS22JFMWW Side by Side Refrigerator
Jan 06, 2009 | Beverage-Air 44.9 cu. ft. / 1271 liter...
Sep 21, 2017 | Heating & Cooling
647 people viewed this question
Usually answered in minutes!