Thermo Products OPB (24, 36)- 80, 30 service manual Preferred method of adjustment

All installations and services must be performed by qualified service personnel.

Preferred method of adjustment:

Using an analog ammeter on the lowest scale, such as an Amp Check, connect the meter across terminals “R” and “W” on the sub-base (“RH” & “W” on an isolating thermostat sub-base). If the reading is too low to move the needle on to the measurement scale of the instrument, proceed as follows.

i.Wrap 10 loops of single strand, insulated, thermostat wire around the prongs of an ammeter, refer to Figure 6. Set the scale to the 1 to 5 or 1 to 6 amp. scale.

Figure 6: Analog Ammeter w/ Wire Loops to Boost Reading

ii.Connect the bare ends of this wire jumper across terminals “R” and “W” on the sub-base (“RH” and “W” on an isolating thermostat sub- base). This test must be performed without the thermostat attached to the sub-base.

iii.Let the heating system operate in this position for about one minute. Read the amp meter scale. Regardless of the value of the meter reading, divide the value by 10 (for 10 loops of wire).

This formula can be used to calculate the correct setting for the

adjustable heat anticipator:

Ammeter reading = Anticipator Setting.

No. of wire loops

29