Nortek Reznor VRA-4E Series, Установка, пусконаладка, обслуживание

Страница: 8 / 25

1712VRA ‐ 4EGBEN, pag.. 8/25
3.4 Air supply 3.5 Air distribution
It is important to ensure that there is an adequate air
supply at all times for both combustion and heating
requirements.
Modern constructions involve the greater use
of insulation, improved vapor barriers and weather
proofing. This practice means that buildings are
sealed much tighter than in the past.
The combustion air supply for a power vented gas
fired air heater (Type B installation) can be affected
by lack of air supply. Natural infiltration may not be
adequate. Use of extract fans aggravates this
situation. It is important to ensure that there is an
adequate air supply at all times. Reliance on doors
and windows is not allowed. Always ensure that an
adequate inlet for fresh air for combustion is
provided sized to suit the total installation of any
combustion apparatus.
Fit an access guard to the combustion air inlet on
the back of the heater and take appropriate action to
ensure that it remains unblocked. See figure 2c.
WARNING: This model air heater is installed as
a type B application and is designed to take air
for combustion from the space in which it is installed.
Do not restrict the combustion air intake.
Figure 2c :
Combustion air and flue pipe sockets, Type
B
1 combustion products flue outlet socket
2 combustion air inlet opening
3 Protection grill (option) (PN 02 25094)
Follow recommended practice for building air
distribution. The following notes are of particular
importance:
"Where free blowing air heaters are installed it must be
taken into account that heated air is buoyant when it
leaves the appliance, therefore, air patterns within the
space being heated will modify the air throw pattern
achieved.
In building having low heat loss where single heaters are
required to cover a large floor area and in buildings with
high ceiling heights, air re-circulation fans may be fitted
to ensure even heat distribution and minimize
stratification. Care should be taken to avoid impeding air
flow with storage racking, partitions, etc."
3.6 Electrical supply
Wiring external to the air heater must be
carried out in accordance with the rules in force
and by
appropriately qualified persons. A
constant 230 Volt 50 Hertz single phase fused
electricity supply with neutral link is required. All
heaters and controls must be earthed. A lockable
isolator with contact separation of at least 3.0
mm on all poles should be installed adjacent to
the appliance and within reach of any person
working on the heater.
When a number of heaters are to be connected
as part of a single installation each heater must
be provided with a separate isolator.
The electrical connection to the air heater is at
the back of the appliance. The final connection
must be made in the terminals provided in the
control compartment. Follow the wiring diagram
provided with the air heater.
Electrical supply cable conductor size should be
1.5 mm. Fit the cord grip supplied with the
heater. The length of conductors between the
cord grip and the terminals must be such that in
the event that the cable becomes taut the line
conductors do so before the earth conductor.
3.7 Gas supply
VRA-4E air heaters are designed to operate on
either natural gas (G20) or propane gas (G31).
Refer to the specifications in section 2 of this
document and to the data plate for details of
supply pressures. The gas meter and gas service
must be checked by the supply undertaking to
ensure that they are adequate to deal with the
total load of all gas fired apparatus installed.