882108-YIM-B-1012
18 Johnson Controls Unitary Products
ELECTRIC HEAT
Units with electric heat are fully wired and operational when
shipped. Constant volume units are designed for two equal
steps of capacity for 80 and three for 108 kWH heat; 40 kW
heat is one step only. Heat outputs on VAV units are all turned
on together at full heat capacity.
HOT WATER HEAT
The YORK Millennium units (25, 30, and 40 Ton sizes) can be
furnished with a YORK hot water coil as the heat source. One
or two row coil units will be factory installed in the heating
section.
NOTE: The hot water control valve will not be provided. The
installer will need to provide a hot water control
valve, to connect the hot water piping and power
wiring at the job site for the hot water heat section to
be operational.
NOTE: For all hot water coils the entering water tempera-
ture should not exceed 200°F.
The hot water coil is located downstream of the supply air fan
and just above the supply air opening in the bottom of the
unit.
Refer to Tables 50 through 58 and Figures 27 through 40 for
flow rate and capacity.
PIPING CONNECTIONS
The hot water piping must enter the unit through the floor of
the heat section compartment. The access doors to the com-
partment are gasketed so the compartment can be sealed.
However, as added protection for water leakage into the
space, the piping access holes should be sealed with a heat
resistant mastic Figure 9 shows the location of the compart-
ment and piping connections.
DO NOT use hot water coils as steam coils under
any circumstances.
All piping, control valves, and wiring that is field
installed must be properly insulated and conform
to all local and national codes.
There are no provisions in the coil or control
sequence to prevent freezing of condensate. The
control valve, piping and field installed wiring con-
nections are particularly vulnerable because they
are installed in the vestibule outside of the condi-
tioned air stream. The installing party will be
responsible for properly insulating and installing
power and control wiring, to the actuator and pip-
ing.
In one row hot water coil systems DO NOT exceed
a 40 gallons per minute flow rate.
In two row hot water coil systems DO NOT exceed
an 80 gallons per minute flow rate.
Condensate will freeze on the control valve and
piping if they are not properly insulated. Insulating
the control valve and piping is the responsibility of
the installing party.
Piping access holes should be sealed with a heat
resistant mastic to prevent damage to equipment.