MTM Hydro Vacuum Switch - 4.0 Hg
MTM Hydro's European Vacuum Switches are used in a variety of methods to turn other items in a pressure washing system on or off. Typically, this switch is used for burner control and is activated by a low pressure vacuum threshold near the pump inlet where this switch is mounted on a 'T' fitting. As you disengage your gun by releasing the trigger, the pressure suddenly spikes which puts your system in bypass and eliminates the low pressure vacuum where the pump draws water. This lack of vaccum triggers the switch to turn an external accessory off (like a burner). Once the trigger is re-engaged, the pressure drops, the unloader upens back up and vaccum resumes allowing the switch to turn the external accessory back on. A few other items switches may operate would include supply pumps, electric pressure washer motors, electronically controlled chemical injection systems. This Vacuum Switch has approximately 4" x 5" x 4" dimensions with ratings of 250 V -16 A.
Be sure to review the specification requirements before purchasing any type of switch as the Hg on a vacuum switch refers to a vacuum measurement in inches of water column. This vacuum measurement is specific to each machine and pump.
You can install this switch in the 'Normally Closed' or 'Normally Open' position depending upon assembly instructions on your pressure washer by connecting to the terminals beneath the outer housing.