EDI Model SM Magnetic Switch System consists of a sealed reed switch for use in above and below ground test stations. The switch is activated by holding a magnet next to the colored band. Green bands denote normally closed switches which are momentarily opened with the magnet. These are most often used for instant-disconnect cathodic protection coupon measurements. Red bands denote normally open switches which are momentarily closed with the magnet. These can be used to electrically isolate a reference electrode in test stations which may become submerged. Magnetic switches are available in Board Mount, Model SM-BRD, or Adjustable Mount, Model SM-ADJ, configurations. Board Mount switches are on a small circuit board with two 9/32 in. (7 mm) dia. holes on 1 in. (25.4 mm) spacing. These switches will fit over adjacent terminals of most test stations. Adjustable mount switches are centered on a length of wire terminating in 9/32 in. (7 mm) ID ring lugs. Ring lugs are spaced at 6-1/4 in. (160 mm). This design is used when the switch must span non-adjacent terminals in a test station.
An activating magnet with a lanyard, Model SM-MAG, is recommended for use with the switches.
Electrical Specifications
- Switching Current: 0.5 amps
- Carry current: 1.0 amp
- Switching Voltage: 175 volts
- Breakdown voltage: min. 200 VDC
- Contact resistance: 150 µohm
- Operating temp.: -40F – 260F (-40C – 130C)