Table of Contents
Advertisement
The size of any pipework attached to a relief valve must
be of sufficient diameter so as not to cause resistance
to the operation of the valve. Unless otherwise speci-
fied by local regulations, table internal diameter depends
on the length of pipe required and is given by the fol-
lowing formula:
D
5
= 1.447 x L
Where:
D =
minimum pipe internal diameter
L =
length of pipe in meters
If relief pipework is common to more than one valve, its
cross-sectional area must be at least the total required
by each valve. Valve types should not be mixed on a
common pipe. Precautions should be taken to ensure
that the outlet of relief valves/vent pipe remain clear of
obstructions at all times.
DUCTWORK CONNECTION
General Requirements
The following ductwork recommendations are intended
to ensure satisfactory operation of the unit. Failure to
follow these recommendations could cause damage to
the unit, or loss of performance, and may invalidate the
warranty.
When ducting is to be fitted to the fan discharge, it is
recommended that the duct should be the same cross
sectional area as the fan outlet and straight for at least 1
meter (3 feet) to obtain static regain from the fan.
Ductwork should be suspended with flexible hangers to
prevent noise and vibration being transmitted to the struc-
ture. A flexible joint is also recommended between the
duct attached to the fan and the next section for the
same reason. Flexible connectors should not be allowed
to concertina.
The unit is not designed to take structural loading. No
significant amount of weight should be allowed to rest
on the fan outlet flange, deck assemblies or condenser
coil module. No more than 1 meter (3 feet) of light con-
struction ductwork should be supported by the unit.
Where cross winds may occur, any ductwork must be
supported to prevent side loading on the unit.
If the ducts from two or more fans are to be combined
into a common duct, back-flow dampers should be fit-
ted in the individual fan ducts. This will prevent recircu-
lation of air when only one of the fans is running.
YORK INTERNATIONAL
Units are supplied with outlet guards for safety and to
prevent damage to the fan blades. If these guards are
removed to fit ductwork, adequate alternative precau-
tions must be taken to ensure persons cannot be harmed
or put at risk from rotating fan blades.
ELECTRICAL CONNECTION
The following connection recommendations are intended
to ensure safe and satisfactory operation of the unit.
Failure to follow these recommendations could cause
harm to persons, or damage to the unit, and may invali-
date the warranty.
No additional controls (relays, etc.)
should be mounted in the control
panel. Power and control wiring not
connected to the control panel should
not be run through the control panel.
If these precautions are not followed
it could lead to a risk of electrocution.
In addition, electrical noise could
cause malfunctions or damage the
unit and its controls.
After connection, DO NOT switch on
main power to the unit. Some inter-
nal components are live when mains
is switched on and this must only be
done by Authorized persons.
POWER WIRING
All electrical wiring should be carried out in accordance
with local regulations. Route properly sized cables to
cable entries on both sides of the unit.
In accordance with U.L. Standard, it is the responsibil-
ity of the user to install overcurrent protection devices
between the supply conductors and the power supply
terminals on the unit.
To ensure that no eddy currents are set up in the power
panel, the cables forming each 3-phase power supply
must enter via the same cable entry.
All sources of supply to the unit must
be taken via a common point of isola-
tion (not supplied by YORK).
FORM 150.52-NM2 (1001)
4
33
Hide quick links:
Advertisement
Table of Contents
