Lochinvar 801, 400 operation manual Flow switch adjustment, Near boiler piping components

6 Hydronic 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.
400	#3			7½ turns
501	#3			5½ turns
601	#3			7¼ turns
701	#3			5¼ turns
801	#3			3¼ turns
		Turn the	sensitivity screw clockwise to
NOTICE
		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

GROUND

COMMON NORMALLY

CLOSED

38

Installation & Operation Manual

Near boiler piping components

1.Boiler system piping:

Boiler system piping MUST be sized per the pipe requirements listed in Table 6B. Reducing the pipe size can restrict the flow rate through the boiler, causing inadvertent high limit shutdowns and poor system performance. Flow rates are based on 20 feet (6 m) of piping, 4 - 90° elbows, and 2 - fully ported ball valves.

2.Boiler system circulating pump:

Field supplied. The boiler circulating pump should be based on 20 feet (6 m) of piping, 4 - 90° elbows, and 2 - fully ported ball valves.

3.Domestic hot water circulating pump:

Field supplied. The pump MUST be sized to meet the specified minimum flow requirements listed in FIG.’s 6-5 and 6-6. Consult the indirect water heater operating guide to determine flow characteristics for the selected product used.

4.Variable speed boiler system circulator:

Knight boilers are capable of controlling a variable speed boiler system circulator. Variable speed circulators MUST be sized to meet the specified minimum flow requirements listed in FIG.’s 6-5 and 6-6 on page 40 at full speed.

5.Boiler isolation valves:

Field supplied. Full port ball valves are required. Failure to use full port ball valves could result in a restricted flow rate through the boiler.

6.Check valves:

Field supplied. Check valves are recommended for installation as shown in FIG.’s 6-7 through 6-11. Failure to install check valves could result in a reverse flow condition during pump(s) off cycle.

7.Domestic indirect hot water isolation valves:

Field supplied. Full port ball valves are required. Failure to use full port ball valves could result in a restricted flow rate through the boiler.

8.Anti-scald mixing valve:

Field supplied. An anti-scald mixing valve is recommended when storing domestic hot water above 115°F (46°C).

9.Unions:

Field supplied. Recommended for unit serviceability.

10.Temperature and pressure gauge:

Factory supplied. The temperature and pressure gauge is shipped loose. It is the responsibility of the contractor to install the temperature and pressure gauge on the boiler water outlet.

11.Pressure relief valve:

Factory supplied. The pressure relief valve is sized to ASME specifications.