Fan Stages; Principle Of Operation - Airstream INTER 2V4SA User Manual

INTER 2V4SA
7. Fan Stages
7.1. Principle of Operation
The INTER 2V4SA controls two stages of vari-
able-speed fans (stages1-2) and four optional
stages of constant-speed fans (stages 3-6).
Fix hysteresis to stop fan stages:
On/off fan stages can either stop when the
room temperature falls below their respec-
tive differential or when it falls 1°C (1,8°F )
below the stage's differential (fix hysteresis).
Set internal switch #10 to the ON position
if you want to use the fix hysteresis of 1°C
(1,8°F ).
Ventilation Level
Stage 6
Stage 5
Stage 4
Stage 3
Stage 2
Stage 1
Stage 1
Min
Min.V.
Set Point
Stage 1 Stage 2 Stage 2
Bandwidth Offset Bandwidth
*Stage 2 starts at its minimum speed and Stage 1 goes to its
"Override Min Speed". Refer to section 7.1.1 on page 17 for
further information about the Stage Merge.
I. If the room temp. rises:
• When room temperature < Set Point,
stage 1 fans run at minimum speed according
to the minimum ventilation cycle.
• At Set Point: stage 1 fans stop operating ac-
cording to the minimum ventilation cycle and
increase in speed as the temperature rises.
• At Set Point + Bandwidth 1: stage 1 fans
reach their full speed.
• At Set Point + Bandwidth 1 + Stage 2
Offset: stage 2 fans start and stage 1 fans
go to their Override Min Speed.
• At Set Point + Bandwidth 1 + Stage 2
Offset + Bandwidth 2: stage 1 and stage 2
fans reach their max speed.
Fan Stages
or
or
or
Stage 3 Stage 4 Stage 5
Differential Differential Differential
or
Stage 6
Room T°
Differential
INTER 2V4SA, rev.02
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