Hot Air Furnace Low-Voltage Wiring
Make the field low-voltage connections at the low-voltage terminal strip shown in Fig. 2-7. Set the thermostat heat anticipator at 0.60 A (or whatever is called for by the manufacturer). If additional controls are connected in the thermostat circuit, their amperage draw must be added to this setting. Failure to make the setting will result in improper operation of the thermostat.
With the addition of an automatic vent damper, the anticipator setting would then be 0.12 A. As you can see from this and the schematic, the anticipator resistor is in series with whatever is in the circuit and is to be controlled by the thermostat. The more devices controlled by the thermostat, the more current will be drawn from the transformer to energize them. As the current demand increases, the current through the anticipator is also increased. As you remember from previous chapters, a series circuit has the same current through each component in the circuit.