Master Bilt GT-80, GT-60, GT-50 manual Refrigeration System And Operation

Models: GT-80 GT-50 GT-60

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REFRIGERATION SYSTEM AND OPERATION

30 Hour Dial

The unit defrost is controlled by a timer in the control box. After removing the condenser grille, the control box will slide out until the defrost timer is visible. The factory set defrost is two times in 24 hours with a maximum timed interval of 30 minutes. The unit contains a defrost termination sensor so in actual use the defrost time will be less than 30 minutes in most cases. The timer can be converted to operate for a timed defrost termination by disconnecting the blue/white from the X terminal. NOTE: When disconnected, it is recommended that the terminal be cut off of the blue/white wire and the wire end be capped with a wire nut.

The defrost time is set by switching a white key from the center to the outside edge of the dial. Each key is 15 minutes so two successive keys must be switched outward for a 30 minute maximum time defrost. If it is noted that more defrost time is needed, then switch outward the third successive key for a 45-minute maximum timed defrost. If another defrost in 24 hours

is needed then more keys can be switched outward as needed. If possible, try to keep defrosts evenly spaced in

a 24 hour period.

30 Hour Dial

Pointer

The current time can be set by turning the outer dial in the direction of the arrow until the correct clock time is shown and the small arrow aligns with either the AM or PM scale.

NOTE: The cabinet serial number for the GT is on the data plate located on the end opposite the condensing unit.

REFRIGERATION SYSTEM AND OPERATION

The cabinet utilizes a Hermetic compressor and operates with refrigerant 404A. Cabinet operates on 115/60/1 power. The cabinet has a bare tube type condenser, which virtually eliminates the possibility of condenser blockage by dust and dirt.

The cabinet operates with a specific charge of refrigerant 404A. The amount of the charge of refrigerant is listed on the cabinet nameplate in ounces. These systems use one or two captubes to meter refrigerant to the evaporator. They include automatic electric defrost systems which are time initiated (by the timeclock) and terminated by a defost termination thermostat which is mounted on a coil supporting bracket in the gravity coil section directly beneath the top of the cabinet. This defrost termination overrides the time clock and turns the compressor back on line when the gravity coil is defrosted. This is the point at which the coil has reached sufficient temperature to incure complete defrost. If the defrost termination control should fail to operate, the time clock will automatically turn off defrost and again turn on the compressor after the 34 minute (or the time interval you selected) interval set on the time clock. If the time clock fails to turn the heaters off, a final back-up safety thermostat will shut off the heaters when gravity coil temperature reaches +80 oF.

Cabinet has a refrigeration system known as automatic defrost gravity coil with cold wall construction. This means the inner liner of the cabinet below the load level line is refrigerated by gravity flow of air from a fin and tube coil, as well as copper refrigerant lines attached to the back of the inner liner tank on all sides and the bottom.

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Master Bilt GT-80, GT-60, GT-50 manual Refrigeration System And Operation