Thomas & Betts LDAP 1200 High Limit Control cont’d, Adjustable Air Destrati- fication Fan Control

18.High Limit Control (cont’d)

19.Adjustable Air Destrati- fication Fan Control

the Maintenance Section for information on probable causes . (For location, see FIG- URE 22, page 33.)

DANGER: If a manual reset high limit control activates, identify and correct the cause before resetting the switch. Never bypass the high limit control; hazardous conditions could result. See Hazard Intensity Levels, page 2.

An adjustable fan control is located on top of the first heat section. It is adjacent to the circulating air fan and motor and controls the fan motors in all heat sections. The purpose of the fan control is to energize the fan motor(s) when the ambient air tem- perature around the heater reaches the setting on the control. The fan motor(s) will be de-energized when the fan control is satisfied. The fan(s) re-circulates the heated air near the ceiling down to the floor level (destratification) and improves heat recovery. A call for heat by the thermostat overrides the air destratification fan control.

Set the adjustable fan control for the desired temperature setting for energizing the circulating air fan(s). The fan control setting should be set 5 to 10°F higher than the wall-mounted thermostat setting. The heater is factory wired to energize the fan(s) at medium speed when energized by the adjustable fan control. For lower mounting heights it may be desirable to operate the fan(s) at low speed. Switching the blue (medium speed) and red (low speed) fan motor wires on each heat section will change the fan motor(s) speed. Refer to the wiring diagram for the wire locations.

To manually override the fan control, the heater may be tuned off at the circuit breaker in the main electrical panel, or a field-installed electrical box with a SPST switch can be located near the wall thermostat with the switch wired in series with the fan con- trol.

The air destratification can also be a benefit in the summer time. Using the fan(s) in the summer time can improve working conditions by alleviating stagnant air condi- tions and creating a cooling effect for the occupants.

20.Ignition System

Each heat section in this heater is equipped with a direct spark integrated control module (circuit board). The module monitors the safety devices and controls the operation of the fan and venter motors and the gas valve between heat cycles.

FIGURE 13 – DSI		x
Integrated Control	Spark
Module (circuit	Transformer	Control Plug
board) in Each			Fuse
Heat Section
			Thermostat
			Connections
Supply
Voltage				Dip
Connections			Fan/Blower	Switch
			Off
			Delay
			Status	LED
				Lights
			Lights
Form RZ-NA-I-LDAP, P/N 207733 (Rev 2), Page 18