Nordyne MB7BM Series User Manual

MODULAR AIR HANDLER
MB7BM, MB7EM, & MB7VM SERIES
INSTALLATION INSTRUCTIONS
DO NOT DESTROY. PLEASE READ CAREFULLY & KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.
IMPORTANT
ATTENTION INSTALLERS:
It is your responsibility to know this product better than your customer. This includes being
able to install the product according to strict safety guidelines and instructing the customer on
how to operate and maintain the equipment for the life of the product. Safety should always be
the deciding factor when installing this product and using common sense plays an important
role as well. Pay attention to all safety warnings and any other special notes highlighted in the
manual. Improper installation of the furnace or failure to follow safety warnings could result
in serious injury, death, or property damage.
Please read all instructions carefully before starting the installation. These instructions are
primarily intended to assist qualified individuals experienced in the proper installation of this
appliance. Some local codes require licensed installation / service personnel for this type of
equipment. If a problem occurs, check the instructions and follow recommendations given.
If these suggestions don’t eliminate your problem, call your servicing contractor. Return this
manual to the customer’s package for future reference.

Nordyne MB7BM Series Specifications

General

Model Number	MB7BM Series
Phase	1
Heating Capacity	Electric Heat Available
Blower Motor Type	ECM
Airflow Range	Up to 2000 CFM
Dimensions (H x W x D)	Varies by Model
Weight	Varies by Model

Summary

Important Safety Information and General Guidelines

Safety Markings and Hazard Warnings

Explains WARNING/CAUTION labels and their significance for hazard levels.

Electrical Shock, Fire, and Explosion Hazards

Details critical electrical safety precautions to prevent severe injury or property damage.

Proposition 65 Warning

Notifies about chemicals in the product known to cause cancer or reproductive harm.

General Information and Installation Prerequisites

Requirements and Codes Compliance

Emphasizes adherence to all local codes, regulations, and national standards for installation.

About the Air Handler Unit

Provides an overview of the unit's testing, efficiency, and need for proper installation/maintenance.

Before You Install: Equipment Inspection and Location

Pre-Installation Inspection and Verification

Steps to inspect for damage, verify power supply, and check duct system suitability.

Minimum Installation Clearances

Specifies required clearances for servicing and proper unit operation as per Table 1.

Unit Location and Placement

Guidance on selecting the optimal location considering access, noise, and unit dimensions.

Operation During Construction Precautions

CAUTIONary notes on potential warranty voiding and damage from improper construction use.

Plenums and Air Duct Installation

Ductwork Installation Standards and Codes

Adherence to NFPA, local codes, and securing/sealing of all duct connections.

Supply and Return Air Duct Design

Guidelines for duct sizing, length, transition fittings, and material requirements.

Acoustical Ductwork and Noise Reduction

Use of acoustical lining, fiber ductwork, and damping methods for noise control.

Air Filters and Condensate Drainage

Air Filter Importance and Handling

Importance of filters, warning against operation without one, and recommended replacement schedule.

Condensate Drainage Requirements

CAUTIONary note on unit leveling for proper condensate drainage to prevent damage.

Air Handler Installation Configurations

Upflow Installation Procedures

Steps for factory-ready upflow configuration, including mating with cased coils.

Downflow Installation Procedures

Instructions for installing the unit in a downflow configuration with cased coil.

Horizontal Installation Guide

Horizontal Left Installation Steps

Detailed instructions for preparing and installing the unit for horizontal left airflow.

Horizontal Right Installation Steps

Detailed instructions for preparing and installing the unit for horizontal right airflow.

Electrical Connections and Safety Precautions

Pre-Electrical Checklist and Verification

Essential checks before making electrical connections, including voltage and wiring.

Line Voltage Wiring and Protection

Guidelines for line voltage supply, disconnects, circuit protection, and wire types.

Thermostat Wiring and Isolation

Instructions for thermostat connections and maintaining isolation for Class 2 circuits.

Control Board and System Components

Control Board Functionality

Explains the control board's role in timing sequences and blower delays.

Heater Kits, EAC, and Humidifier Integration

Information on field-installed heater kits, EAC, and humidifiers.

Grounding Requirements

Critical safety warning on the need for proper electrical grounding and prohibited methods.

Startup and Adjustments Procedures

Pre-Startup Inspections and Checks

Comprehensive list of checks before initial unit operation for safety and performance.

Air Circulation and System Checks

Procedures for checking blower operation, system cooling, and system heating modes.

Blower Configuration and Airflow Settings

Selecting Minimum Electric Heat Airflow

Guide to setting minimum airflow for electric heat operation using switches or wires.

Determining Nominal System Capacity

How to identify the correct system capacity for setting appropriate airflows.

High Efficiency Unit Airflow Optimization

Instructions for optimizing performance of Variable & Fixed Speed High Efficiency units.

Dehumidification Mode Configuration

Options for enabling and configuring dehumidification using thermostat or humidistat inputs.

Unit Maintenance Procedures

Blower Fan Wheel and Motor Inspection

Guidance on inspecting and cleaning the blower fan wheel and motor assembly.

Cooling Coil and Drain Pan Cleaning

Steps for cleaning the cooling coil, drain pan, and condensate drain for optimal performance.

Unit Maintenance and Troubleshooting

Air Filter Inspection and Replacement

Importance of filters, warning against operation without one, and replacement schedule.

Blower Compartment Cleaning

Recommends cleaning the blower compartment to prevent overheating and motor damage.

Troubleshooting Common Issues

Checklist for diagnosing and resolving common air handler operational problems.

Figures and Tables Overview

MB7 Series Physical Dimensions Diagram

Illustrates the physical dimensions (A, B, C) of the MB7 Series air handler cabinets.

Component Location Guide

MB7 Series Component Locations Diagram

Provides an exploded view identifying the key components within the MB7 Series unit.

Blower Performance Data Tables

MB7BM Airflow Performance Data

Table detailing airflow (CFM) for MB7BM units across various ESP and cabinet sizes.

MB7EM Airflow Performance Data

Table showing airflow (CFM) for MB7EM units based on switch settings and ESP.

MB7EM Minimum Heating Airflow Settings

Table for MB7EM (FSHE) specifying minimum heating airflow by cabinet and KW.

MB7VM Recommended Cooling Airflow Settings

Table for MB7VM recommending cooling airflow by cabinet size and nominal capacity.

MB7VM VSHE Airflow Performance Data

Table detailing airflow (CFM) for MB7VM VSHE units based on settings and operation mode.

Electrical Data and Wiring Diagrams

Minimum Circuit Ampacity and Overcurrent Protection

Table providing essential electrical data (MCA, MOP) for MB7BM and MB7(E,V)M models.

Typical Thermostat Wiring Diagrams

Visual guides for connecting thermostats to various air handler and system configurations.

MB7BM Single Stage Control Board Diagram

Diagram showing the layout and terminals of the MB7BM single-stage control board.

MB7EM/VM Two-Stage Control Board Diagram

Diagram showing the layout and terminals of the MB7EM/VM two-stage control board.

MB7EM Fixed Speed Motor Control Board Diagram

Diagram of the motor control board for MB7EM fixed speed models, showing fan speed and status.

MB7VM Variable Speed Motor Control Board Diagram

Diagram of the motor control board for MB7VM variable speed models, showing fan speed and inputs.

MB7BM Series Air Handler Wiring Diagram

Detailed wiring schematic for MB7BM series, including notes and legend for field/factory wiring.

MB7EM Series Air Handler Wiring Diagram

Detailed wiring schematic for MB7EM series with fixed speed high efficiency motors.

MB7VM Series Air Handler Wiring Diagram

Detailed wiring schematic for MB7VM series with variable speed high efficiency motors.

Heating Element Logic Tables

MB7BM Heating Element Logic

Table detailing control signals, operation, and board actions for MB7BM heating stages.

MB7EM/MB7VM Heating Element Logic

Table detailing control signals, operation, and board actions for MB7EM/MB7VM heating stages.

MB7EM/MB7VM Heating Element Logic (Continued)

Continuation of the heating logic table for MB7EM/MB7VM series air handlers.

Installation and Performance Checklist

Electrical System Checks

Checklist items for verifying electrical connections, voltage, and thermostat settings.

General Installation and Owner Review

Verifies proper unit installation, leveling, drainage, and owner information review.