Grounding; Thermostat Connections; Control Board; Heater Kits - Maytag B6BM series Installation Instructions Manual

• If replacing any of the original wires supplied with the unit,
the replacement wire must be copper wire consisting of
the same gauge and temperature rating.
• Provide power supply for the unit in accordance with the
unit wiring diagram, and the unit rating plate. Use UL listed
conduit and conduit connectors for connecting the supply
wires to the unit and for proper grounding. Field supplied
bushings for the power supply cables must be added to
support and protect the power supply cables.
• All 208/230 Volt units are shipped from the factory wired for
240 volt operation. For 208V operation, remove the lead
from the transformer terminal marked 240V and connect
it to the terminal marked 208V.

Grounding

wARNING:
the unit cabinet must have an uninterrupted or
unbroken electrical ground to minimize personal
injury if an electrical fault should occur. Do not
use gas piping as an electrical ground!
This unit must be electrically grounded in accordance with
local codes or, in the absence of local codes, with the National
Electrical Code (ANSI/NFPA 70) or the CSA C22.1 Electrical
Code. Use the grounding lug provided in the control box for
grounding the unit.

thermostat connections

• Thermostat connections shall be in accordance with the
instructions supplied with the thermostat. The thermostat
used with this equipment must operate in conjunction
with any installed accessories. Typical AC and air handler
hookups are shown in Figure 10 (page
cAutIoN:
Isolation must be maintained from the external
class 2 output of any transformer in a cooling
circuit. use a thermostat with isolating contacts
to prevent inter-connection of class 2 outputs.
• Where local codes require that the thermostat wiring must
be routed through a conduit or raceway, splices can be
made inside the unit; however, all wiring must be NEC
Class 1 and separated from incoming power leads.
• The thermostat should be mounted about 5 feet above the
floor on an inside wall. DO NOT install the thermostat on
an outside wall or any other location where its operation
may be adversely affected by radiant heat from fireplaces,
sunlight, or lighting fixtures, and convective heat from
warm air registers or electrical appliances. Refer to the
thermostat manufacturer's instruction sheet for detailed
mounting and installation information.
• Install the grommet, which is packed with the unit, in the
hole for low-voltage wires. Properly connect the low-voltage
wiring between the thermostat, outdoor unit, and control
board. NotE: When the low voltage wires are positioned
in this grommet, the grommet will prevent chafing and/or
shorting of the low voltage leads.

control Board

The control board in the air handler controls the timing
sequence of the elements. The board is equipped with a 3
second blower on delay and a 15 second blower off delay
in heating and a 40 second blower off delay in cooling. See
Figure 14 (page 18)
12 (page 29)

Heater Kits

When electric heat packages with circuit breakers are field-
installed, the circuit breaker may be used as a disconnecting
means in most applications. Reference the NEC and local
codes for disconnect requirements.
If a heater kit is installed:
B6BM, B6EM, & B6VM air handlers are shipped from the
factory without an electric heater kit installed. If electric heat
is desired, a heater kit may be purchased separately and
field installed. Determine the correct size heater kit for your
unit by referring to the list below or the units rating label.
A-Size Cabinet ............................................... 15Kw max
B-Size Cabinet ............................................... 20Kw max
C-Size Cabinet .............................................. 30Kw max
1. Connect the 2 wire plug of the air handler to the mating 2
wire plug of the heater kit.
2. Connect the line voltage leads to the circuit breaker or
terminal block provided.
3. Connect the heater kit plug with the mating receptacle on
the air handler control board.
If a heater kit is not installed:
1. Remove the 2 wire plug of the air handler by cutting the
wires and discarding the plug.
2. Strip the ends of the 2 air handler wires and connect to
12). the line-voltage leads with the 2 wire nuts provided.

Electronic Air cleaner (EAc)

The unit has an output to power an electronic air cleaner
when the blower is running. This output is rated to 1.0 amp
at 208/240V.

Humidifier

The unit has an output to power a humidifier when the blower
is running. This output is rated to 1.0 amp at 208/240V.

optional Humidistat

(B6EM or B6VM Models Only)
The optional humidistat may be installed in the return air
duct to provide excellent humidity control when needed
and maximum system capacity and energy efficiency when
humidity levels are normal. The humidistat senses when
humidity in the return air stream is above a preset level
(field adjustable) and sends a signal to the motor to reduce
the airflow so that more moisture may be removed until the
humidity level drops. The air handler is pre-programmed for
humidistat operation.
Install the humidistat in the return air duct as directed in
the installation instructions included with the kit. Wire the
humidistat through the low-voltage wire entrance in the air
handler to the control board terminal marked DEHuM. See
Figure 16 (page 23)
humidistat to close on rise in humidity.
or Figure 15 (page 23)
for control board modes and actions.
& Figure 17 (page
and Table
24). Wire the
11