Master Bilt IM-23GB - Manual (Page 10)

10
ELECTRICAL CONNECTIONS
The controller is provided with screw terminal block to connect cables with a cross section up to 2,5 mm
2
. Before
connecting cables make sure the power supply complies with the control’s requirements. Separate the probe cables
from the power supply cables, from the outputs and the power connections. Do not exceed the maximum current
allowed on each relay, in case of heavier loads use a suitable external relay.
PROBE CONNECTIONS
The probes shall be mounted with the bulb upwards to prevent damage due to casual liquid infiltration. It is
recommended to place the thermostat probe away from air streams to correctly measure the average room
temperature. Place the defrost termination probe among the evaporator fins in the coldest place, where most ice is
formed, far from heaters or from the warmest place during defrost, to prevent premature defrost termination.
SERVICE INSTRUCTIONS
1. High head pressure and high back pressure:
A. Condenser coil clogged or restricted
B. Condenser fan motor defective.
C. Air discharge in rear of cabinet restricted.
2. Low back pressure and low head pressure:
A. Restriction in system.
B. Refrigerant
undercharged.
C. Leak in system
3. Pressure normal – cabinet warm:
A. Coil blocked with frost (see #4).
B. Refrigerant
undercharged.
C. Control set too warm.
4. Ice merchandiser not cycling – coil blocked with frost:
A. Defective temperature controller, or improper settings.
B. Refrigerant
overcharged.
C. Location too hot.
D. Condenser
clogged.
E. Condenser fan motor defective.
F. For freezer, defrost heater not operating.
G. Air leakage into ice merchandiser due to open door or faulty door seal.
5. Compressor starts and runs – but cycles on overload:
A. Low voltage
B. Relay defective.
C. Overload defective.
D. High head pressure (see #1).