Aiko CTH3-200 Manuale Utente

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SECTION 10: W
IRING
  
47 of 71
For 4-20mA control of the heater(s) firing rate, the 
following control conditions apply:
ON/OFF relay at the external controller or BMS must 
be wired to R and W terminals on the heater control 
board to turn the heater ON and OFF. 
(Open Circuit = OFF, Closed Circuit = ON).
Minimum rated input at 1% of signal (0-4 mA).
Full rated input at 90% of signal (18 mA).
Input varies linearly between 4 mA and 18 mA.
BMS controllers often offer PID loop control that can 
optimize output signal and rate of change of the 
output signal. Common analog application is defined 
as follows:
1. BMS sensors that monitor zone air
temperatures are located in the heating space.
2. Based on sensed temperatures, the BMS will 
output an analog signal for the desired heater(s) 
firing rate.
3. As heater(s) receive the analog signal from the 
BMS, the heater(s) modulate to the correspond-
ing firing rate.
4. As sensed air temperature rises closer to the 
desired temperature setpoint, the BMS will 
reduce the output signal, in turn reducing heater 
firing rate.
5. Upon satisfying temperature setpoint, the BMS 
will either:
a. Turn off the heater.
b. Reduce the signal so that the minimum 
heater firing rate is maintained until the 
sensed temperature rises above the       
setpoint to a cut-off limit temperature when 
the BMS turns off the heater.
FIGURE 27: Analog Control Signal Wiring Diagram
*OPTIONAL
SWITCH
SATELLITE HEATER CONTROL
FOR SATELITTE 
CONTROLLERS, J9 JUMPER CAN BE 
LEFT IN ORIGINAL POSITION
REGARDLESS OF CONTROL METHOD.
J10 JUMPER POSITION 
SHOWS "SATELLITE" DESIGNATION.
MODULATION CONTROL WIRING 
TO ADDITIONAL SATELLITE 
HEATER CONTROL TERMINALS
T28 and T29.
ON/OFF SWITCH
REQUIRED
MODULATION CONTROL WIRING 
TO SATELLITE HEATERS
CENTRAL HEATER CONTROL
REMOTE ANALOG 
CONTROL 
SIGNAL FROM SEPARATE  
CONTROLLER
0-10Vdc OR 4-20mA
ANALOG INPUT CONTROL IS 
USED TO SELECT ANALOG 
SIGNAL TYPE 0-10Vdc OR 4-20mA 
(4-20mA POSITION SHOWN).
J10 JUMPER POSITION 
SHOWS "CENTRAL" 
DESIGNATION AND 
"ANALOG" CONTROL METHOD.
J10
J9
W
R
-
+
-
+
-
+
OUT
RA
TE
FIRI
N
G
IN
RA
TE
FIRI
N
G
EXT
. PO
T
G
N
D
W
IPER
HIGH
G
N
D
BA
R
SLIDE
G
N
D
THERMIS
T
OR
IN
PUT
A
N
AL
OG
THERMOSTAT
T31
T29
T19
T18
T16
T14
T27
T25
T30
T28
T17
T15
T13
T26
T24
-
+
J10
J9
W
R
-
+
-
+
-
+
OUT
RA
TE
FIRI
N
G
IN
RA
TE
FIRI
N
G
EXT
. PO
T
G
N
D
W
IPER
HIGH
G
N
D
BA
R
SLIDE
G
N
D
THERMIS
T
O
R
IN
PUT
A
N
AL
OG
THERMOSTAT
T31
T29
T19
T18
T16
T14
T27
T25
T30
T28
T17
T15
T13
T26
T24
A  B
A  B
* Separate on/off switch is optional for "satellite" heaters (install at user level). On/Off switch is used to 
disable heater operation or reset a heater that is in "lockout" mode. If on/off switch is not desired, leave 
jumper wire between R and W terminals in place.