Variable Speed Motor & Control Installation Instructions - Variable Speed Motor Conversion Parts List

Oct 24, 2026

Upload by Riley

Installation instructions for a variable speed motor and control conversion kit, covering 90+ and 80+ kit number configurations for designated 8MPT/9MPT series B and C PSC and MPV motors. The addendum must be kept with the furnace literature, including complete safety requirements, hazard signal word definitions, and technician-only installation guidance. Includes compatibility limits, notes on blower speed settings, and part verification. Provides detailed kit contents and wiring/installation instruction references by model.

LanguageEnglish

CategoryTechnology

FormatPDF

Pages29

Reading Time1 h 13 min

AccessFree to download

Safety Requirements

Safety-alert symbol and signal words

Trained personnel and precautions

Safety codes and protective equipment

Kit Overview and Compatibility

Purpose of the conversion

Series/model restrictions and exclusions

Backward compatibility and control terminal notes

Installation Guidance

Verify included parts

Blower speed and circulation air data

Harness and TSIB usage rules

Variable Speed Motor Conversion Parts List

*8MPT/*8MPV series B models

*9MPT/*9MPV series C models

INSTALLATION INSTRUCTIONS For Variable Speed Motor & Control 90+ Kit Numbers: NAHL050VBB NAHL075VBB, NAHL100VBB, NAHL125VBB 80+ Kit Numbers: NAHA050VBE, NAHA075VBE, NAHA100VBE, NAHA125VBE This kit is designed to do the following: —Convert *8MPT series B and *9MPT series C (excluding the *8MPT100F14B model) PSC motor toa two--stage cooling compatible variable speed motor. —Convert *8MPV series B and *9MPV series C single--speed cooling variable speed motor to a two--stage cooling compatible variable speed motor. This literature is an addendum to the Installation Instructions provided with the furnace. Keep the conversion kit installation instruction with the furnace literature. * Denoted Brand (T, H or C) Please read these instructions completely before attempting installation. SAFETY REQUIREMENTS Recognize safety information. This is the safety--alert symbol ! . When you see this symbol on the furnace and in instructions manuals be alert to the potential for personal injury. Understand the signal words DANGER, WARNING, or CAUTION. These words are used with the safety--alert symbol. DANGER identifies the most serious hazards, those that will result in severe personal injury or death. WARNING signifies a hazard that could result in personal injury or death. CAUTION is used to identify unsafe practices that may result in minor personal injury or product and property damage. NOTE is used to highlight suggestions that will result in enhanced installation, reliability, or operation. Installing and servicing heating equipment can be hazardous due to gas and electrical components. Only trained and qualified personnel should install, repair, or service heating equipment. Untrained service personnel can perform basic maintenance functions such as cleaning and replacing air filters. All other operations must be performed by trained service personnel. When working on heating equipment, observe precautions in the literature, on tags, and on labels attached to or shipped with the unit and other safety precautions that may apply. Follow all safety codes. In the United States, follow all safety codes including the current edition National Fuel Gas Code (NFGC) ANSIZ223 . 1--2006/NFPA No. 54--2006. In Canada, refer to the current edition of the National Standard of Canada Natural Gas and Propane Installation Code (NSCNGPIC) CSA B149 .1--05. Wear safety glasses and work gloves. Have fire extinguisher available during start--up and adjustment procedures and service calls. These instructions cover minimum requirements and conform to existing national standards and safety codes. In some instances, these instructions exceed certain local codes and ordinances, especially those that may not have kept up with changing residential construction practices. We require these instructions as a minimum for a safe installation. Examine Kit to determine that the following parts are present. If any parts are missing, immediately contact your parts supplier. See Backward Compatibility Section for cooling off--delay operation update for these series models: Example showing series letter: *8MPT050B12 B 1 --All *8MPT series B and *9MPT series C models --All *8MPV series B and *9MPV series C models --Furnace controls with Y/Y2 terminal identified on the furnace control board have no need for correction. This kit is NOT set up to work with *8MPT/Vseries A or *9MPT/V series B models. (Smartvalve ignition/Megellan, different kit required.) See Changing Blower Speed Section, Circulation Air Blower Data Tables and Charts for setting and adjusting desired blower speeds for continuous fan, heating and cooling operation. All parts in kit must be installed according to specifications provided for correct operation. On MPV conversion models--DO NOT reuse old VS motor harness with new Tap Select Interface Board (TSIB) and motor. Specifications are subject to change without notice 441 06 2020 00 July 2006 Variable Speed Motor Con

FAQs

What is the purpose of this addendum kit installation literature?

It provides installation guidance for converting specified PSC and single-speed cooling variable speed motors into a two-stage cooling compatible variable speed motor, as an addendum that must be kept with the furnace installation instructions.

Who is allowed to install or service this heating equipment?

Only trained and qualified personnel should install, repair, or service the heating equipment. Untrained service personnel may perform basic maintenance like cleaning or replacing air filters; other operations must be done by trained service personnel.

Which furnace control or model compatibility notes affect installation?

Controls with a Y/Y2 terminal identified on the furnace control board have no need for correction. The kit is not set up for certain *8MPT/*9MPT series A/B variants (including Smartvalve ignition/Megellan), and a different kit is required.

Oct 24, 2026

Upload by Riley