Application Guide

Pressure Dependent VAV Applications with MEP-4002 17 CTE-5202 Applications Guide, AN0912A Rev. H
~
T T
AI1
AO1 AO2
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 VAC
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
ow” voltage signal (AO1) is connected to the MEP-
4002 to adjust airow from minimum to maximum
ow according to space demand. Minimum and
maximum ow 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 Change Conguration on
page 6.
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 seing (55° F).
See Change Conguration 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.