Operation - Honeywell Pressuretrol P7810C Quick Start Manual

MODUTROL ®
7800 SERIES
1
PROGRAMMER MOTOR
HIGH
12
3
237
8K1
OHM
COMMON
13
8K2
MODULATION
15
9K1
3
66.5
OHM
9K2
LOW
14
6
L2 4
120 VAC LINE
VOLTAGE
DEVICE WIRING
FIELD WIRING
1 7800 SERIES SHOWN. REFER TO SPECIFICATIONS PACKED WITH THE
PROGRAMMER FOR WIRING OF OTHER PRIMARY SAFETY CONTROLLERS.
2 MODUTROL® MOTOR MUST BE MODUTROL III OR MODUTROL IV,
SERIES 90, ELECTRONIC BALANCE RELAY TO OPERATE AS SHOWN.
3 PART OF 4074EDC OR 4074EED BAG ASSEMBLY ORDERED SEPARATELY.
MAKE SURE LIMITS VOLTAGE SUPPLY IS CONNECTED TO COM TERMINAL.
4
Fig. 4. Wiring diagram for typical P7810
installation using Series 90 Modutrol® Motor.
HIGH FIRE
8K1
COMMON
8K2
MODULATE
9K1
9K2
LOW FIRE
7800 SERIES PROGRAMMER
Fig. 5. Firing Rate Wiring Diagram using P7810C,D Pressuretrol® Controller and Series 90
Modutrol Motor with Manual Position Potentiometer and Auto-Manual Switch.
P7810 PRESSURETROL ®
2
CONTROLLER
B
R
–
4 TO 20mA
+
W
2K1 1K1
N.O.
L1
L2
COM
4
120 VAC LINE
LIMITS
VOLTAGE
M11892A
6
12
2
237
OHM
13
15
2
66.5
OHM
14
B
MANUAL
R
AUTOMATIC
W
P7810C,D PRESSURETROL
Replace the front cover after completing the wiring.
Wiring for the 4 to 20 mA operation is shown in Fig. 5.

OPERATION

The P7810C,D uses integral electronic pressure sensors to
sense pressure at the inlet. The sensed pressure and input
setpoint energize a separate relay for the control function, a
separate relay for the limit function and output a 4 to 20 mA
modulation signal for the modulation function. A more detailed
explanation of the functions of the devices follows.
The P7810C and D include an internal steam pressure
manifold (see Fig. 6) which consists of two 1/4 in. NPT
(1/4 NPS) connections to the steam pressure header. The
internal steam pressure manifold provides separate sensing
elements and operating switches. The sensors provide:
a. Steam pressure control (on-off/modulate—P7810C
only). The function of this sensor is to shut off the fuel
supply to the boiler or system through the Flame
Safeguard control when the steam pressure reaches a
preset operating pressure (on-off) setpoint. In addition,
the P7810C provides a 4 to 20 mA output current that
adjusts to match firing rate to steam pressure changes.
b. Steam pressure safety high limit control causes a safety
shutdown and lockout when the steam pressure
reaches a preset safety high limit setpoint.
B
R
W
MODUTROL ®
MOTOR
B
1
S443A AUTO/MANUAL CONTROL WITH INTERNAL
1
135-OHM POTENTIOMETER.
R
2 PART OF 4074EDC BAG ASSEMBLY OR 4074EED
BAG ASSEMBLY, ORDERED SEPARATELY.
W
MAKE SURE LIMITS VOLTAGE SUPPLY IS
3
CONNECTED TO COM TERMINAL.
5
®
CONTROLLER
2K1
NO
1K1
COM 3
LIMITS
–
L1
120V
LINE
+ VOLTAGE
L2
P7810 CONTROLLER
M11894A
65-0235—1