What occurs to the pressure in the suction pipe when the load on a DX evaporator is increased and the compressor cannot move the extra gas?

When the load on a DX (Direct Expansion) evaporator is increased and the compressor is unable to move the extra gas, the pressure in the suction pipe will rise. This phenomenon occurs because as the load increases and the evaporator absorbs more heat, the refrigerant in the evaporator can evaporate at a higher temperature if the compressor cannot keep up with the increased demand for gas.

When the compressor cannot remove the additional refrigerant vapor effectively, the evaporator's pressure will increase due to the accumulation of the refrigerant gas in the suction line. The compressor's inability to handle the extra load leads to a condition where the pressure builds up in the suction pipe instead of remaining steady or dropping. This is indicative of an imbalance between the evaporation and compression processes within the system.

Understanding this behavior is crucial for diagnosing issues within the refrigeration cycle and maintaining optimal performance of the DX system. The other answer choices do not accurately reflect the dynamics that occur under these circumstances, which involve the interaction between the evaporator load and compressor function.