FUNCTIONAL DESCRIPTION

Control Power

Control power of 24 Vdc/Vac, 32 Vdc/Vac, 48 Vdc/Vac, or 120 Vdc/Vac is

applied at terminals 1 and 2. (The MOC model number determines the

nominal input voltage level.) As necessary, it is rectified and decreased

to 24 Vdc at terminals 3 (negative) and 4 (positive). This 24 Vdc is applied

to the motor through a network of external switches which allow application

of the 24 Vdc in either polarity. The polarity is determined by the need to

raise or lower the system parameter controlled by the MOC.

Potentiometer Output

The potentiometer serves as the adjusting element of the MOC and is

connected to terminals 14. 15. and 16. The potentiometer wiper arm,

connected to terminal 15. moves toward terminal 14 when a raise

command is received. A lower command moves the wiper arm to move

toward terminal 16. Terminals 8 and 13 are connected internally to switches

that provide the centering feature for the potentiometer wiper arm.