York MILLENNIUM Y22, Installation Manual

Page: 20 / 140

102777-YIM-E-0206
20 Unitary Products Group
NOTE: The steam control valve, power and control wiring to
the actuator of the valve is the responsibility of the
installing party.
PIPING CONNECTIONS
Refer to Tables 54 through 57 and Figures 50 and 51 for flow
rate and capacity.
The steam piping must enter the unit through the floor of the
heat section compartment. The access doors to the compart-
ment are gasketed so the compartment can be sealed. How-
ever, as added protection for condensate leakage into the
space, the piping access holes should be sealed with a heat
resistant mastic. The following figure illustrates the location of
the compartment and piping connections.
STATIC PRESSURE CONTROL PLASTIC TUBING
On units with inlet guide vanes (IGV's) and variable fre-
quency drives on the supply blower and/or power exhaust
fans, pressure sensing tubing must be field supplied and
installed from differential pressure switches or transducers to
the locations in the building or ductwork where a constant
pressure is desired, and to the atmosphere.
The supply air discharge static pressure switch or transducer
is located in the blower compartment on the heat section par-
tition panel. Plastic tubing (1/4") must be run from the high
pressure tap of the transducer to a static pressure tap (field
supplied) in the supply duct located at a point where constant
pressure is desired. Tubing must also be run between the low
pressure tap of the transducer to atmospheric pressure.
EXHAUST STATIC PRESSURE
If a modulating power exhaust is installed, there will be a
building pressure sensor (BPS) in the control box directly
below the Millennium Simplicity. This ± .25 0-5VDC trans-
ducer sends a building pressure signal to the control. A sens-
ing tube must be installed from a representative location in
the building to the HI power of the transducer.
Changing the adjustment is done to the building pressure
parameter in the control.
All piping and control valves, and wiring that is
field installed must be properly insulated and con-
form 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.
DO NOT use steam coils as hot water coils under
any circumstances.
In steam coil systems, the steam pressure shall
not exceed 15 PSI.
Piping access holes should be sealed with a heat
resistant mastic to prevent damage to equipment.
DO NOT use tin based solder. Brazing with tin
based solder could cause equipment damage or
possible injury to tenets of the structure that is
being conditioned.
Do not run plastic tubes in the supply or return air
ducts as air movement could cause erroneous
sensing. If tubes penetrate bottom of unit be sure
openings are sealed against air and water leak-
age.