Description
DESCRIPTION The WM 81 series consists of non-grounded switches that respond to a drop of air pressure below a preset level. The WM 81 switches feature an adjustment that allows the actuation setting to be modified. The switches are shipped from the factory with this setting preadjusted to 50-60 PSI (344,7-413,7 kPa). When the pressure drops below the preset value, these switches activate a light or buzzer to indicate that a low pressure condition exists.
OPERATION When the control pressure exceeds the preset level, a diaphragm in the switch holds the contacts in the open position. If the pressure decreases below this level, the diaphragm is spring-returned and the contacts close. A customer-supplied light or buzzer warns the operator of the low pressure condition.
APPLICATION The WM 81 series single-pole, single-throw switches are commonly installed as signal devices in pneumatic braking systems. Designed for low voltage (6-24 VDC), low amperage applications, these switches are frequently used to activate a warning light or buzzer when a low pressure condition exists in the vehicle's air brake system. The WM 81 series is not UL approved.
