Lochinvar 497 - 2067 service manual Burners, Terminal strip connection options

5 Electrical connections

External EMS connection to terminal strip for stage firing control of

Installation & Service Manual

Figure 5-2_Stand-alone operation

burners

This unit is equipped with a factory installed terminal strip for connection of an energy management system (EMS) to the burner stages. The EMS terminal strip is located in the unit’s control panel. Ensure that all wiring used for connection to this terminal strip is properly sized per the recommendations in TABLE 5A. When connecting an EMS to this terminal strip to sequence on each stage of burner operation, the unit’s internal thermostat or electronic sequencer should be set as an additional high limit control. This will prevent problems between the set

1	+	SYSTEM/TANK
2	+	SENSOR

3+ B2 INTERMITTENT

4+ B1 LIMITS

5+ A2 CONTINUOUS

6+ A1 LIMITS

7	+	2 NO HIGH FIRE
8	+	2 C	ENABLE
9	+	1 NO LOW FIRE
10	+	1 C	ENABLE

6

7

8

9

10

1

2

3

4

5

points of the EMS and the boiler’s internal controller.

Figure 5-3_Remote on/off boiler or water heater

Terminal strip connection options

Figure 5-2 shows the position of jumpers as shipped from the factory for stand-alone operation of boilers or water heaters.

Figure 5-3 shows connections to the terminal strip for Remote ON/OFF control of the boiler or water heater. The 1C-1NO jumper must be removed when making these wiring connections. This remote ON/OFF control will provide an Enable/Disable signal to the unit and allow the unit to operate based on the stage set points, until the remote ON/OFF signal is cancelled.

	1	+	SYSTEM/TANK
	2	+	SENSOR
	3	+	B2 INTERMITTENT
	4	+	B1	LIMITS
	5	+	A2	CONTINUOUS
Remote	6	+	A1	LIMITS
	7	+	2 NO HIGH FIRE
on/off
	8	+	2 C	ENABLE
	9	+	1 NO LOW FIRE
	10	+	1 C	ENABLE

6

7

8

9

10

1

2

3

4

5

Figure 5-4 shows the connections necessary to operate the unit as a two-stage (High/Low Fire) boiler or water heater from an Energy Management System (EMS). The actual

Figure 5-4_Two-stage (high/low fire) boiler or water heater

set point temperatures are controlled by the EMS. The High Fire Offset on the electronic temperature control in the unit must be set to zero and the set point must be set to a value which will function as an upper limit for proper operation under this two-stage control from an EMS.

Figure 5-5 shows the Continuous and Intermittent terminals. External safety devices connected to these terminals will function to protect the unit. Devices connected to the Intermittent terminals (B1 and B2) are monitored only when there is an active Call for Heat. Devices connected to the Continuous terminals (A1 and A2) are monitored continuously and will activate

	1	+	SYSTEM/TANK
	2	+	SENSOR
	3	+	B2 INTERMITTENT
	4	+	B1	LIMITS
	5	+	A2	CONTINUOUS
Stage 2	6	+	A1	LIMITS
	7	+	2 NO HIGH FIRE
	8	+	2 C	ENABLE
	9	+	1 NO LOW FIRE
Stage 1	10	+	1 C	ENABLE

6

7

8

9

10

1

2

3

4

5

an alarm (if the unit is equipped with the alarm option) anytime the safety device senses an abnormal condition.

Figure 5-5_Field installation safety devices

38

	1	+	SYSTEM/TANK
Intermittent	2	+	SENSOR
Alarms	3	+	B2 INTERMITTENT
	4	+	B1	LIMITS
	5	+	A2	CONTINUOUS
Continuous	6	+	A1	LIMITS
	7	+	2 NO HIGH FIRE
Alarms	8	+	2 C	ENABLE
	9	+	1 NO LOW FIRE
	10	+	1 C	ENABLE

6

7

8

9

10

1

2

3

4

5