Carrier 58MCA 12SI Gas Furnace Owners Manual

Two-Speed Furnace Control Replacement Kit Cancels: NEW IIK 340M-40-86 10-04 Installation Instructions Part No. 325879-751 NOTE: Read the entire instruction manual before starting the installation. SAFETY CONSIDERATIONS Installing and servicing of heating equipment can be hazardous due to gas and electrical components. Only trained personnel should install or service heating equipment. Untrained personnel can perform basic maintenance functions such as cleaning and replacing filters.

All other operations should be performed by trained service personnel. When working on heating equipment, observe precautions in the literature, on tags, and on labels attached to the unit. Follow all safety codes. Wear safety glasses and work gloves. Have a fire extinguisher available. Recognize safety information. This is the safety-alert symbol. When you see this symbol on the furnace and in instructions or manuals, be alert to the potential for personal injury. Understand the signal words DANGER, WARNING, and CAUTION. These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies a hazard which could result in personal injury or death. CAUTION is used to identify unsafe practices which may result in minor personal injury or product and property damage. NOTE is used to highlight suggestions which will result in enhanced installation, reliability, or operation. 3. All 115-volt neutrals are grouped together in one location of board. (See Fig. 3.) 4. Humidifier connection is removed from thermostat terminal block. It is now a ¼ inch spade terminal, next to the thermostat terminal block. (See Fig. 3.) KIT CONTAINS Control board Wire harness adapter Kit Wiring diagram PART NUMBER HK42FZ017 328156-701 328155-101( Rev A) TWINNING The control board in this kit CAN also be twinned with any of following circuit boards Part No. HK42FZ005, HK42FZ010, and HK42FZ015. ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD Failure to follow this warning could result in possible damage to this equipment, serious personal injury, or death. The ability to properly perform service on this equipment requires certain expertise, mechanical skills, tools, and equipment. If you do not possess these, do not attempt to perform any service on this equipment other than those procedures recommended in the User’s Manual. INTRODUCTION This kit is a direct replacement for circuit boards Part No. HK42FZ005, HK42FZ010, and HK42FZ015. Changes to the operation of this control include: 1. The blower off delay selections are: 90, 120, 150 and 180 seconds. 2. A DHUM connection has been added to the thermostat terminal block. When connected to a thermidistat and when there is a call to dehumidify the cooling airflow will be reduced to high-heat airflow. When jumpered to Y/Y2 it will reduce the 90 second blower-off delay in the cooling mode, to 5 seconds. UNIT DAMAGE HAZARD Failure to follow this caution may damage furnace components. Electrostatic discharge can affect electronic components. Take precautions during furnace installation and servicing to protect the furnace electronic control.