Electric compensation, back-pressure regulator

as a rule, found in the upper part of the controller. In electrically compensation regulator, turning the stem to get different pressure and temperature of the refrigerant in the evaporator is a small electric motor. This motor rotates the adjustment of the stem in accordance with temperature fluctuations in the thermostatic bulb placed in the medium cools down as it leaves the evaporator. Adjusting rod, spring, and control the diaphragm were separated from their positions in the top of the controller. They were placed in a small remote mounted on a common base with motor and gearbox drive. This compensating devices can be placed in any convenient place in 20 metres from the main regulator. The device connects two small pipelines. These bring pressure changes, established by the iris.

The overall arc of the motor speed and the big gear motor acting through the smaller gear adjustment stalk membrane will rotate stem about two turns. This is sufficient to cause the knob to change the pressure in the evaporator through the full range of about 13 pounds (see Fig. 10-27).

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