Fresh Air; Constant Flow Fresh Air Controller; Fresh Air Duct As Optional Accessory - Carrier 42BJ ULTRA Series Installation Manual

5 - FRESH AIR

5.1 - Constant flow fresh air controller

The 42BJ ULTRA can be fitted with a constant fresh air flow
controller allowing the number of air changes to be controlled.
It is vital to choose the correct constant fresh air flow control-
ler for the use to which the room or zone concerned will be
put.
The following range of controllers is available:
- 30 m /h or 8.3 l/s (-10%; + 20%)
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- 60 m 3 /h or 16.6 l/s (-10%; + 20%)
The fresh air supply inlet is located upstream of the water coil.
The 125 mm spigot which houses the flow controller is made
of ABS.
16.7 l/s (60 m 3 /h) 20.8 l/s (75 m
27.8 l/s (100 m 3 /h) 36.1 l/s (130 m
The 60 m /h or 16.6 l/s fresh air controller may be modified on
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site by relocating or removing two plastic restricters in order
to increase its constant fresh air flow capacity to a maximum
of 160 m 3 /h or 44.4 l/s.
A label on the 42BJ shows how to readjust the two plastic res-
tricters.
FRESH AIR CONTROLLER
Modification procedure:
• Disconnect the fresh air duct from the plastic spigot on the
ULTRA.
• Remove the fresh air controller from inside the spigot.
• Move or relocate the two plastic restricters.
• Replace the fresh air controller in the spigot.
• Reconnect the fresh air duct to the spigot.
16
3 /h)
3 /h) 44.4 l/s (160 m 3 /h)
NOTE:
Two types of plastic spigot may be fitted to the ULTRA,
depending on the capacity of the fresh air controller chosen.
One spigot can accept only the 8.3 l/s or 30 m
The other one can accept only the field modifiable 16.6 l/s or
60 m 3 /h controller. This means there is no possibility of
mixing up the two types of controller during installation or
servicing.
If the ULTRA is fitted with a return air temperature sensor,
the constant fresh air flow rate must not exceed 50% of the
air flow rate delivered by the unit at minimum speed.
NOTE:
To operate correctly, the 8.3 l/s or 30 m
flow controller requires a differential pressure in the range
50 Pa to 200 Pa. The 16.6 l/s or 60 m
controller requires a differential pressure in the range 70 Pa
to 200 Pa.

5.2 - Fresh air duct as optional accessory

Flexible fresh air duct, diameter 125 mm, maximum length
500 mm, fitted with two coupling sleeves integral with the
duct (the duct fire rating is M1).
3 /h controller.
3 /h constant fresh air
/h constant fresh air
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