To make a shift to a test mode by using another method even when there is no method for access to a main control board by providing a plurality of methods for shifting to the test mode.

A means for shifting to the test mode that enables execution of the shift by a plurality of switches different in a position of installation is provided. The means for shifting to the test mode can be made to have one or more of the following functions. The shift to the test mode is made by the switch provided on the main control board. The shift is made by a key switch operated from the time when a power source is made. It is made by the switch provided on the main control board in a normal operation. It is made by the key switch in the normal operation. The shift from the test mode to the normal operation is made by the switch provided on the main control board. This shift is made by the key switch.