Lochinvar 399 Near boiler piping connections, Flow switch adjustment, Circulator sizing

Installation & Operation Manual

6Hydronic piping

Flow switch adjustment

Refer to Table 6A for the proper setting of the sensitivity screw. For reference, the position of the screw prior to setting should be turned clockwise with a Phillips driver until it stops (FIG. 6-3). Proceed to turn the screw counterclockwise the amount of turns listed in Table 6A based on the model.

Consult the manufacturer’s instructions for wiring the flow switch to your system.

Table 6A Paddle Size / Sensitivity Screw Adjustment

MODEL	PADDLE SIZE	SENSITIVITY SCREW
		ADJUSTMENT
Note: Paddles are included with the flow switch.
399	#3	7½ turns
500	#3	5½ turns
600	#3	7¼ turns
700	#3	5¼ turns
800	#3	3¼ turns

Near boiler piping connections

Figure 6-4ANear Boiler Piping w/Y-Strainer

SYSTEM

FROM

		DOMESTIC HOT
SYSTEM PUMP		WATER PUMP	INDIRECT
			DOMESTIC
		FROM HOT WATER
	SYSTEM	TO	TANK
TO
	BOILER PUMP
	Y-STRAINER
	(RECOMMENDED)

NOTICE

Turn the sensitivity screw clockwise to increase the flow rate required to activate the switch. Turn the sensitivity screw counterclockwise to decrease the flow rate required to activate the switch.

Figure 6-3Flow Switch Adjustment

NORMALLY

OPEN

SENSITIVITY

ADJUSTMENT

TO FLOOR

DRAIN

Figure 6-4BNear Boiler Piping w/Low Loss Header

GROUND

COMMON NORMALLY

CLOSED

Circulator sizing

SYSTEM PUMP

SYSTEM SENSOR

AIR SEPARATOR

DRAIN

(TYPICAL)

AIR VENT VALVE LOW LOSS HEADER (TYPICAL)

TO	SYSTEM
SYSTEM
FROM

EXPANSION TANK

FAST FILL VALVE	INDIRECT
DRAIN VALVE	DOMESTIC
FROM HOT WATER
TO	TANK

The Knight XL heat exchanger does have a pressure drop, which must be considered in your system design. Refer to the graphs in FIG’s 6-5 and 6-6 for pressure drop through the Knight XL heat exchanger.

36

Y-STRAINER (RECOMMENDED)

TO FLOOR

DRAIN