The Murphy 30Hg Mechanical Vacuum Swichgage A20V-30 is a diaphragm-actuated, vacuum-indicating gage with a built-in electrical switch. This switch is used for tripping alarms and/or shutdown devices. The A20V-30 has a polycarbonate case and is sealed from the environment, it also features a polycarbonate, break-resistant lens and a polished, stainless steel bezel to help protect this rugged, built-to-last instrument.
The gage pointer acts as a pressure indicator and as one switch pole which completes a circuit when it touches the adjustable limit contact. Contacts have a self-cleaning motion to ensure electrical continuity. A pulsation dampener (PD2160) is included to help eliminate pointer flutter. When monitoring intake manifold vacuum, the PD2160 is mounted in the manifold. The PD2160 has a 1/8-27 NPT connection.
Commonly used to measure loading of spark ignition engines through intake manifold vacuum. Also can serve as overspeed protection from sudden loss of load on these engines. Use anywhere the vacuum source is compatible with port materials.
- 2 inch/51 mm dial
- Combination Indicating Gage and Limit Switch
- Monitor Engine Load
- Switch Can Activate Alarms and/or Shutdown Equipment
- Polycarbonate/glass filled
- Part No.: A20V-30
- Range: 0-30 inches of Hg
- Dial: White on black, dual scale
- Case (mounting clamp included): Polycarbonate/glass filled
- Bezel: Polished stainless steel
- Lens: Polycarbonate, high-impact
- Process Connection: 1/8-27 NPTM brass
- Sensing Element: Beryllium copper diaphragm
- Gage Accuracy: ±2% of scale in operating range (mid 1/3 of scale)
- Adjustable Limit Contacts: 2-SPST contacts; pilot- duty only, 2 A @ 30 VAC/DC. Contacts are gold flashed silver
- Limit Contact Adjustment: by a 1/16 in. hex wrench
- Limit Contact Terminals: Number 4 screw terminals
- Unit Weight: 6 oz. (0.17 kg)
- Unit Dimensions: 3 x 3 x 3 in. (76 x 76 x 76 mm)