Bryant 549B User Manual
Page 42
—
42
—
3. Set DCV maximum position potentiometer to previ-
ous setting.
4. Set minimum position, DCV set point, and exhaust
potentiometers to previous settings.
5. Remove 620-ohm resistor from terminals S
R
and +.
6. Remove 1.2 kilo-ohm checkout resistor from termi-
nals S
O
and +. If used, reconnect sensor from termi-
nals S
O
and +.
7. Remove jumper from TR to N.
8. Remove jumper from TR to 1.
9. Remove 5.6 kilo-ohm resistor from T and T1. Recon-
nect wires at T and T1.
10. Remove jumper from P to P1. Reconnect device at P
and P1.
11. Apply power (24 vac) to terminals TR and TR1.
Table 25 — EconoMi$er IV Input/Output Logic
*For single enthalpy control, the module compares outdoor enthalpy
to the ABCD set point.
†Power at N terminal determines Occupied/Unoccupied setting:
24 vac (Occupied), no power (Unoccupied).
**Modulation is based on the supply-air sensor signal.
††Modulation is based on the DCV signal.
***Modulation is based on the greater of DCV and supply-air sensor
signals, between minimum position and either maximum position
(DCV) or fully open (supply-air signal).
†††Modulation is based on the greater of DCV and supply-air sensor
signals, between closed and either maximum position (DCV) or fully
open (supply-air signal).
INPUTS
OUTPUTS
Demand Control
Ventilation (DCV)
Enthalpy*
Y1
Y2
Compressor
N Terminal†
Outdoor
Return
Stage
1
Stage
2
Occupied
Unoccupied
Damper
Below set
(DCV LED Off)
High
(Free Cooling LED Off)
Low
On
On
On
On
Minimum position
Closed
On
Off
On
Off
Off
Off
Off
Off
Low
(Free Cooling LED On)
High
On
On
On
Off
Modulating** (between min.
position and full-open)
Modulating** (between
closed and full-open)
On
Off
Off
Off
Off
Off
Off
Off
Minimum position
Closed
Above set
(DCV LED On)
High
(Free Cooling LED Off)
Low
On
On
On
On
Modulating†† (between min.
position and DCV maximum)
Modulating†† (between
closed and DCV
maximum)
On
Off
On
Off
Off
Off
Off
Off
Low
(Free Cooling LED On)
High
On
On
On
Off
Modulating***
Modulating†††
On
Off
Off
Off
Off
Off
Off
Off
Fig. 42 — EconoMi$er IV Functional View