Pressure Dependent VAV Applications with MEP-4002
17
CTE-5202 Applications Guide, AN0912A Rev. D
~
T
T
AI1
AO
1
AO
2
CTE-5202
Thermostat
24 VAC @ 5 VA
~
–
(Phase)
(Neutral)
(5K–10K
Ohm Resistor
between AI1
and Common
for Heating
Mode Only)
MEP-4002
Actuator
24 V
A
C
Common
Input
Out
Cooling or Heating
CTE-5202 thermostats can use MEP-4xx2 actuators
to operate damper boxes in a pressure-dependent
VAV system. As shown in the diagram, a “requested
flow” voltage signal (AO1) is connected to the MEP-
4002 to adjust airflow from minimum to maximum
flow according to space demand. Minimum and
maximum flow limit adjustments can be made at the
thermostat (recommended) or at the actuator. (See
the
MEP-4000 Series Installation Guide
For
cooling
, select Sequence
1
(from the CTE-5202
SYSTEM
menu). See
.
Heating Air
Heating Max.
Heating Min.
1650
fpm
0 fpm
Setpoint
(
Colder
Room Temperature
Warmer
)
3300
fpm
Cooling Max.
Cooling Min.
1650
fpm
0 fpm
Setpoint
(
Colder
Room Temperature
Warmer
)
3300
fpm
AO1
Signal
Cooling Air
AO1
Signal
Select Sequence 1
Select Sequence 1
AND set Changeover to 55° F
For
heating
, connect a 5K to 10K ohm resistor
between Common and AI1. Select Sequence
1
and
lower the Changeover to the lowest setting (55° F).
See
Change Configuration on page 6
. The resistor
simulates a changeover sensor and puts the thermo
-
stat in Reverse Acting mode.
NOTE: If the resistor value is too high, the
thermostat will not go into RA mode. If
the resistor value is too low, the thermostat
may go into setback mode.