Cut-out relay adjustment

Cut-out relay adjustment

Ascertain the type of regulator fitted and then wire to the test unit as shown in FIG 11:10 or FIG 11:12. Before the unit is assembled to the test bed the instruments should be set as follows:

P - at minimum so that voltmeter reads zero.

T — open.

R - all inserted giving maximum resistance.

T - open.

1 Contact closing voltage

This test should be carried out at an ambient temperature of 25°±10°C. Close the switch T and stabilize the regulator thermally by feeding current into it for approximately 15 to 18 minutes at 16.5 volts which is obtained by adjusting P for initial regulator operating temperatures of between 15°-20°C or at 15 volts for initial operating temperatures of 20°-35°C. Once the stabilizing of the regulator has been completed bring the voltage to 12 6± .2 volts by adjusting P. Adjust the load on the setting spring by bending the relevant arm until the pilot light S is extinguished. Reset P to minimum and again increase the voltage by P and check that the pilot lamp is extinguished at the specified voltage.

2 Reverse current

This test must be carried out at a temperature of 25°± 10°C and it is recommended that it is carried out as soon as possible after the closing voltage test so as to maintain minimum regulator thermal stability. With the switch T closed bring the voltage to 14.5 volts by operating P. The contacts of the cut-out should be closed and the pilot lamp S off. Close T and increase the reverse current by means of the rheostat R and check that the pilot lamp S glows as the contacts part. The opening may also be unsteady which will be indicated by a slight buzz from the unit. Check the value of the ammeter of the reverse current causing the opening of the contacts and this should not exceed 16 amps. If the reading is unstable or S lights up at the recommended limit reset the reverse current to the minimum value and repeat the test once more. Finally open the switches T and T and again adjust rheostat R and P to the minimum settings.