Application Note; Steam Pressure Load Control - Honeywell S7999B Manual

Application:
Description:
Digital Inputs: None
Analog Inputs: Steam pressure sensor (0-750
psi) (4-20mA)
Setpoints:
Modulation (0-500°F or 0-750 psi)
On-Off (0-500°F or 0-750 psi)
Low Fire Hold (0-500°F or 0-750 psi)
Application File:
steam01.nge
Range
Controller
Model (see
footnote)
Algorithm:
CTRALG
TIMER
Output:
OUTALG
CURRENT
Input 1:
IN1TYP
4–20 mA
IN1 HI
IN1 LO

APPLICATION NOTE

Steam Pressure Load Control

On-off and modulating outputs to start/stop and adjust firing rate to maintain a control
setpoint.
steam02.nge steam03.nge
0–15 psi 0–15 psi 0–150 psi
LOW FIRE
1 2
PIDA PIDA
DIS DIS
CURRENT CURRENT
4–20 mA 4–20 mA
15 15
0 0
L1
L2
250 OHM
RESISTOR
+
-
STEAM
PRESSURE
SENSOR
(STD 904
SERIES)
Digital Outputs:
Analog Outputs:
steam04.nge steam05.nge
0–150 psi 0–300 psi
LOW FIRE
1 2
PIDA PIDA
DIS DIS
CURRENT CURRENT
4–20 mA 4–20 mA
150 150
0 0
65
S7999B SYSTEM DISPLAY
G +
UDC
CONTROLLER
L1 -
L2
25 R
26
+
SHIELD D+ D-
-
27 16 17 18
C A B
MODBUS COMMUNICATION
HONEYWELL S7810M
On-Off relay
Optional: Modulation Alarm1 (ON
when at or below Modulation setpoint,
OFF when above Modulation setpoint)
Optional: Low Fire Hold Alarm2 (ON
when at or below Low Fire Hold
setpoint, OFF when above Low Fire
Hold setpoint)
PID modulation (4-20mA) to control
firing rate. Modulation based on
modulation setpoint.
steam06.nge steam07.nge
0–300 psi 0–750 psi
LOW FIRE
1 2
PIDA PIDA
DIS DIS
CURRENT CURRENT
4–20 mA 4–20 mA
300 300
0 0
19 FIRING RATE
MOTOR
21
INTERFACE
5 L1
6
8
L1
9
ON–OFF
CONTROL
BURNER
CONTROL
M24242
steam08.nge
0–750 psi
LOW FIRE
1 2
PIDA PIDA
DIS DIS
CURRENT
4–20 mA
750 750
0 0
65-0283—2