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Mitsubishi Electric PAC-646BH-E Quick Start Manual

Heater base parts optional conditioner-air packaged


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Before installation
• This product is designed for prevention of ice on the bottom of the outdoor unit heat exchanger and the clogged drain hole caused by
freezing in severe winter.
• To drain properly, a drain socket and a concentrated drain pan are not allowed to be used with this product.
• Carefully read this section 'Safety Precautions', and securely install the optional parts.
• Be sure to observe the cautions described here: They include critical contents for safety.
• The following indications show the classifications for danger, and possible consequences following incorrect handling.
Incorrect handling could lead to death or serious injury.
Incorrect handling could lead to injury or damage to house and household articles.
• After installation, perform a test run and make sure that there is no abnormality, and ask your customer to keep this installation sheet
with the installation manual at all times.
Also ask the customer to transfer these manuals to a new user if the user changes.
Ask the dealer or specialist for installation.
• If installed incorrectly by user, water leak, electric shock, fire, etc.
could result.
Use the provided parts and the specified parts for installation.
• Improper parts could cause electric shock, fire, water leak, and
injury caused by fall of the unit.
Mount the service panel on the outdoor unit securely.
• Incomplete installation may result in electric shock and fire
caused by dust, water, etc.
Do not install the unit where flammable gas may exist or leak.
• If the flammable gas should leak and accumulate around the unit,
explosion may result from it.
Install an earth leakage breaker.
• Failure to install an earth leakage breaker may result in electric
Packaged Air-Conditioner Optional Parts
Base Heater
Carefully install the optional parts according to this instal-
lation sheet.
• Incorrect installation could cause water leak, electric shock, fire,
Use the specified electric wires. Connect and fasten the
electric wires securely to the terminals so external force on
the wires will not apply on the terminals.
• Improper connections and fastening could cause fire.
Ground the unit correctly.
• Do not connect the ground wire to a gas pipe, a water pipe, a
lightning rod, or a telephone ground wire. Improper grounding
may cause electric shock.
The grounding is performed with your hands touching the fins of
the heat exchanger. Wear protective equipment such as gloves
and the like in advance.
1 Accessories
This package includes the following parts besides this installation sheet.
1 Base heater
1 2 Heater support U
5 Cable tie
3 6 Fastener
9 Screw M4×8
8 0 Self-drilling screw
2 Preparation
It is easier to mount the base heater before installing the outdoor unit.
• Make sure that the main power supply to the unit is OFF.
• Do not lose the removed screws. Many screws will be removed to install the base heater.
• Eliminate dust, dirt, etc.
3 Before installation
Before installation, follow the procedures below to remove some parts from the outdoor unit.
NOTE: Turn OFF power supply before disassembly.
1) Remove the screw fixing the service panel.
2) Remove the service panel.
3) Remove the screws fixing the top panel.
4) Remove the top panel.
5) Remove the screws fixing the front panel.
6) Remove the front panel.
7) Remove the screws fixing the back panel.
8) Remove the back panel.
9) Disconnect the connectors (CN791, CN792, CN712, CNTH2,
CNTH1, CN797, CN63H, CNF1, and relay connector), and
remove the electrical box.
10) Removal of propeller fan.
Remove the mounting screws for the propeller fan. Pull the
propeller fan toward you to remove it.
11) Removal of motor support.
Disconnect the connector of the fan motor, and remove
mounting screw for the motor support. Slightly pull the motor
support toward you and lift it up to remove it.
12) Remove the rear guard.
Front panel
(Fig 1)
2 3 Heater support L
2 4 Heater plate
2 7 Earth plate
1 8 Earth wire
2 1 Spec label
1 2 Cable strap
Top panel
Electrical box
Back panel
Motor support
Propeller fan
Service panel
Rear guard



Summary of Contents for Mitsubishi Electric PAC-646BH-E

  • Page 1 This package includes the following parts besides this installation sheet. Base Heater 1 Base heater 1 2 Heater support U 2 3 Heater support L 2 4 Heater plate PAC-646BH-E Before installation 5 Cable tie 3 6 Fastener 2 7 Earth plate 1 8 Earth wire •...
  • Page 2 4 Preparation for mouting the base heater 6 Securing the lead wires [OUTDOOR CONTROL P.C. BOARD] 1) Fix the heater support U 2 and L 3 to the base heater 1 with 2 screws M4×8 9 (2 places) as shown in the Fig 2. Wiring diagram CN714 (Place the heater supports as they fit in the drain holes).