Each of these conditions will result in lower than normal operating pressures. When there is a shortage of refrigerant, pressures will be lower than normal. However, the reduction in pressure may be so slight as not to be readily detected, other than by a loss of evaporating capacity and the longer running time of the unit. If the shortage is considerable, both suction and discharge pressures will be very low; if the system temperature control consists of a thermostat only, the unit will run continuously with poor refrigerating effect. When a low pressure switch is in circuit, the compressor will short cycle (cut in and out quickly) on.
