Vibration Isolators
Spring Isolation
Device
Motor / Blower Assembly
in Shipping Position
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After the unit is set in its final location, visually inspect
motor / blower assembly to verify presence of spring
isolation devices. If they are present, carefully remove
shipping restraints to allow for free movement of the
assembly.
The method of compressing and restraining the
motor / blower assembly varies with each product.
If sheet metal screws or bolts are used, they are
installed with an equal number on both the front and
the rear of each assembly. Screws or bolts used on
the rear rail are difficult to see. It is recommended
that the rear screws or bolts be removed before the
front ones in order to reduce the chance of injury. If
restraining bands are used instead of screws or bolts,
carefully cut and remove the bands.
Plumbing / Piping Overview
The only piping connections required are the
condensate drain trap and gas connections for the
optional gas furnace(s).
Condensate Drain Trap
This unit is equipped with a stainless steel condensate
pan with a stainless steel drain connection. It is
important that the drain connection be fitted with a
P trap to ensure proper drainage while maintaining
internal static pressures and to prevent migration of
sewer gas back into the unit. A P trap assembly (kit)
is supplied with the unit and is to be assembled and
installed as local conditions require and according to
the assembly instructions provided with the P trap. If
local and area building codes permit, the condensate
may be drained from the P trap onto the roof, but a
drip pad should be provided beneath the outlet. If
local and area codes require a permanent drain line, it
should be fabricated and installed in accordance with
Best Practices and all codes.
In some climates it will be necessary to provide freeze
protection for the P trap and
drain line. The P trap should
be kept filled with water or
glycol solution at all times and
it should be protected from
freezing to protect the P trap
from damage. If severe weather
conditions occur, it may be
necessary to fabricate a P trap
and drain line of metal and
install a heat tape to prevent freezing.
Gas Connections
If the model is equipped with an indirect gas-fired
furnace, connection to an appropriate gas supply
line will be required. For complete information on
installation procedures for the optional gas furnace(s),
refer to Indirect Gas-Fired Furnace, Model PVF.
Typical Gas Supply Connection
Ground
Joint
Union
8 in. Trap
Gas to
Controls
From Gas Supply
Bleeder Valve or
1/8 in Plugged Tap
Gas Cock
NOTE
Many motor / blower assemblies include optional
spring vibration isolation devices. When these
isolation springs are used, the motor / blower
assembly is secured for shipment by compressing
the springs and securing the assembly to
intermediate rails (see photo).
NOTE
These assemblies are shipped with the springs in
a compressed state and when shipping restraints
are removed, the assembly will bounce upward.
Do not position hands or fingers where they may
be pinched or injured by sudden movement of the
assembly.
8
Model MPX Make-Up Air Unit
Model XMPX Make-Up Air Unit
