CleaverBrooks CFC-500 Operation, Service And Parts Manual page 153

STEAM HEATING
(CH)
CH ENABLE
CH MODULATION SENSOR
IGNORED: S1 IS ALWAYS USED AS
THE CH SENSOR FOR STEAM
S1 INLET
4-20 mA
S2 4-20 mA
CH
MINIMUM
PRESSURE
EnviraCOM TOD
TOD
CH
PRESSURE
SETPOINT
CH TOD
PRESSURE
SETPOINT
TOD
MODBUS
STEAM SETPOINT
The function of each parameter and feature is given below.
.
Parameter
Steam enable
Steam demand source
Steam sensor
PRESSURE SENSOR TYPE:
0-15PSI OR 0-150PSI
A
4-20 mA
ERROR SCALING:
TO SETPOINT
PRESSURE ERROR IS
NORMALIZED:
1.0 PSI ERROR = 1.0˚C ERROR
1
T
FOR A 150 PSI SENSOR.
0.1 PSI ERROR = 1.0˚C ERROR
2
FOR A 15 PSI SENSOR.
WHERE = MEANS
3
T
"IS EQUIVALENT TO"
T
NO DATA TIMEOUT
REVERT TO SETPOINT
CH SETPOINT SOURCE
1 = S2 4-20mA REMOTE
2 = LOCAL
3 = MODBUS
Fig. 11. Central heating steam diagram.
Table 10. Central Heating Steam Parameters.
Disable, Enable
Disable/enable steam feature.
STAT and Sensor, Remote Stat and Sensor, LCI and Sensor, Sensor Only
The CH demand source may be selected from four options. In all cases, for burner demand
to exist, the sensor must be generating a demand as determined by setpoint and hysteresis
values.
• When "Sensor Only" is chosen, no other input is considered and pump demand is derived
from burner demand.
• When "STAT and Sensor" is chosen, the STAT input in the On condition creates pump
demand and it also must be on for burner demand to exist; if it is off there is no demand.
• When "Remote Stat and Sensor" is chosen, a message indicating the remote stat is on
creates pump demand and it also must be on for burner demand to exist; if the message
indicates this stat is off or if no message has been received within the message timeout
time (3–4 minutes), there is no demand.
• When "LCI and Sensor" is chosen, the LCI input in the On condition creates pump
demand and it also must be on for burner demand to exist; if it is off there is no demand.
Inlet
The sensor used for modulation and demand may be either the Outlet sensor, the 4-20mA
Inlet sensor.
CH DEMAND SWITCH
STAT
EnviraCOM REMOTE STAT
LCI
STAT2
MODULUS STAT
J7-3 120 VAC
HYSTERESIS
CH PRESSURE ON HYSTERESIS
CH PRESSURE OFF HYSTERESIS
PID
P-GAIN
I-GAIN
D-GAIN
RESTART (RESTART
INTEGRATOR WHENEVER
A LIMIT OR OVERRIDE
ENDS, OR TURN-ON
OCCURS.)
Comment
29
STEAM ONLY
PARAMETER
PARAMETER
"pRATE" = 0 TO 99.99%
OF CAPACITY
T
NO DATA TIMEOUT
REVERT TO OFF
T
SENSOR ONLY
SETPOINT DEMAND
BURNER
STATE: ON/OFF
TIME SINCE:
BURNER TURN-ON
BURNER TURN-OFF
4-20 mA
A
1
T
TO
pRATE
2
T
3
T
NO DATA TIMEOUT
REVERT TO PID
MODBUS
RATE
CH MODULATION RATE SOURCE
1 = S2 4-20mA
2 = LOCAL
3 = MODBUS 0-FF
4 = MODBUS 0-200
CB FALCON
INPUT
OUTPUT
T
CH HEAT
DEMAND
CH BURNER
DEMAND
750-265