Twinning; Line & Low Voltage Connections; Refrigerant Piping; Startup & Adjustments - Maytag B6BM series Installation Instructions Manual

twINNING

These instructions are to be used when connecting two B5 or
B6 air handlers (2-5 ton models) to a common single stage
A/C condensing unit or heat pump. Twinning is possible for
B5 units with PSC or X-13 motors and B6 units with PSC
or fixed speed (FSHE) motors. Twinning is not possible for
units with variable (VSHE) speed motors. All low voltage
wiring instructions, cautions, and warnings accompanying
the air handler remain applicable, except for:
Line & Low Voltage connections
a. The line voltage connections for both air handlers must
be the same phase and on the same leg of power.
b. When matched with an S3BM or an S3BW series AC
outdoor unit, both air handler's 24V transformers must
be removed from the control circuit by removing and
discarding the RED wire located on the transformer's
secondary. These outdoor units come standard with 24V
power supply sufficient for powering both air handlers.
c. Low voltage wiring should be connected as shown in
Figure 11 (page 12).
d. Wire all other low voltage thermostat terminals to both air
handlers as shown in Figure 10 (page

Refrigerant Piping

wARNING:
Air conditioner and heat pump equipment
contain liquid and gaseous refrigerant under
pressure. Installation and servicing should only
be attempted by qualified, trained personnel
thoroughly familiar with the equipment and safe
responsible refrigerant handling procedures.
Failure to comply with this warning could result
in equipment damage, personal injury, or death.
The refrigerant piping to each air handler (or coil) should be of
equal length and size. Run the copper pipes from condensing
unit to a point equidistant between the air handlers (or coils).
Place a tee in the lines at this point. After the tee (as close to
the air handler as practical), reduce the pipe size to match
the piping of the air handler or coil.

Before You Start the unit

Prior to start-up, complete the following inspections:
√ Verify the unit is level and properly located with adequate
clearances for servicing the unit as shown in
4).
√ Check condensate drain line(s) for proper drainage.
√ Verify the surrounding area and top of the unit is free from
obstructions and debris.
√ Check all duct connections. Make sure the duct work is
adequately sealed to prevent air leakage.
√ Check all coil connections for leaks.
√ Verify that the line voltage power leads are securely
connected and the unit is properly grounded. Make sure
all doors are installed before restoring power to the unit
√ Verify the thermostat is wired correctly. Make sure all low
voltage wires are securely connected.
√ Verify the power supply branch circuit overcurrent protection
is sized properly.
√ Verify filter is properly and securely installed.
IMPoRtANt: Before starting the unit, install the initial
12). charge on units that are factory shipped with a nitrogen
holding charge:
1. Read all installation instructions first.
2. Purge the nitrogen holding charge.
3. Evacuate the unit to 350 - 500 microns.
4. Allow the unit to remain under vacuum for at least 30
minutes.
5. Weigh in the proper amount of new (or reclaimed)
refrigerant. Refer to the air conditioner or heat pump
installation manual for the proper type and quantity of
refrigerant.

Refrigerant charging

the evaporator coil is shipped from the factory
with a nitrogen charge. use caution when
preparing coils for field connections. If repairs
make it necessary for evacuation and charging,
it should only be attempted by qualified,
trained personnel thoroughly familiar with this
equipment. Some local codes require licensed
installation service personnel to service this
type of equipment. under no circumstances
should the equipment owner attempt to install
and/or service this equipment. Failure to comply
with this warning could result in equipment
damage, personal injury, or death.
The system refrigerant charge can be checked and adjusted
through the service ports provided at the front panel of the
outdoor unit. Use only gauge lines which have a Schrader
depression device present to actuate the valve.
StARtuP & ADjuStMENtS
wARNING:
HEALTH
FLAMMABILITY
REACTIVITY
0 Minimal Hazard
Table 1, (page
NITROGEN
1
0
0
1 Slight Hazard
13