Cycle/Sample Boiler Controller Model 250 from Lakewood Instruments

The Model 250 Boiler Controller measures conductivity using the sample/cycle technique. The Model 250 is intended to control boiler water dissolved solids by measuring and controlling the surface blowdown water conductivity. By measuring the blowdown conductivity, the controller is capable of holding the boiler water conductivity with excellent results. This control results in considerable fuel savings by preventing excessive blowdown. The controller also protects the steam lines by preventing carry-over due to excessive conductivity.

The Model 250 uses the sample/cycle technique and is intended for boilers of less than 1,000 lb./hr under normal operating loads.

Inputs
Power		120 VAC
		120/240VAC w/-F
Sensor		2 electrode Conductivity
Sensor (SR2)
Pressure		600 psi (41.4 bar)
Max. Temperature		486°F (252° C)
Body		Carbon Steel
Electrode		416SS
Insulator		PEEK
Connection		¾ inch MNPT
Outputs
Relays		3 Amps @ 120 VAC
0-1 mA		Non isolated
4-20 mA		Isolated, w/-35
Controller
Conductivity Range		0-10,000 µS
Accuracy		±100 µS
Resolution		100 µS
Deadband		Adjustable
Setpoint		0-10,000 µS
High Alarm		Adjustable
Sample Time		0-10 min
Cycle Time		0-180 min
Ambient Temperature		32-158° F (0-70° C)
Electrical Rating		UL Listed
Enclosure Rating		ABS Plastic

250		Cycle/sample type conductivity blowdown controller with high alarm. 1-10 min sample, 1-180 min cycle time. UL listed. Standard range 0-10,000 µS (No power cord or outlets.) Requires sensor below and PL5 is recommended.

SYSTEM OPTIONS (optional, select one or more)
AV		Audible and visible alarm with "PUSH TO SILENCE" pushbutton.
-CR		0-5 range front panel; conductivity range is 0-5,000 µS.
-2		Remote preamp input (use with SR2P or SR4P, below).
-F		250 VAC 50 Hz power option.

CONTROLLER OUTPUT OPTIONS (optional, select one only)
-35		Isolated 4-20 mA output for conductivity remote data acquisition.
-42		HIGH/LOW conductivity dry alarm contacts with adjustable setpoints.
-44		Isolated 4-20 mA output, plus High/low alarms.

SENSOR OPTIONS (recommended, select one below)
SR2P		Boiler water sensor with preamp & enclosure (only w/-2 above); rated to 600 psi @ 486°F (41.4 bar @ 252°C).
SR4P		4 electrode sensor with preamp & enclosure (only w/-2 above); rated to 250 psi @ 392°F (17.2 bar @ 200°C).
SR2		Boiler water sensor with 20 ft cable, ¾ inch NPT; rated to 600 psi @ 486°F (41.4 bar @ 252°C) with elbow.

PLUMBING OPTIONS (recommended, select one below)
PL5		Plumbing for cycle sample assembly, ½ inch (1/8 & 1/16 orifice plates and union).
PL575		Plumbing for cycle sample assembly, ¾ inch (1/8 & 1/16 orifice plates and union).
GV		½ inch forged globe valve for flow metering instead of an orifice plate and union.

MOUNTING OPTIONS (optional, select one only)
PM		Panel mount 6 ¼ inch square cutout.
BM		Bracket for pipe mounting.

BLOWDOWN VALVE OPTIONS (optional, select one only)
MBV1		Motorized ½ inch blowdown valve with 1036 actuator; rated to 250 psi @ 400°F (17.2 bar @ 204°C).
MBV2		Motorized ¾ inch blowdown valve with 1036 actuator; rated to 250 psi @ 400°F (17.2 bar @ 204°C).
MBV3		High pressure motorized ½ inch blowdown valve with 1275 actuator; rated to 600 psi @ 550°F (41.4 bar @ 288°C).
MBV4		High pressure motorized ¾ inch blowdown valve with 1275 actuator; rated to 600 psi @ 550°F (41.4 bar @ 288°C).
PV4		Pneumatic high pressure ½ inch blowdown valve with 1034 actuator; rated to 600 psi @ 486°F (41.4 bar @ 252°C).