Single Phase & Three Phase AC Current
AC Current General Description
ALTA® Wireless AC Current Meters and ALTA® Industrial Wireless Three-Phase Current Meters continuously measure the alternating current root mean square (AC RMS) using current transformers that clip around the wire in single-phase and three-phase power systems.
Key Features
Three current transformer sizes available for single-phase and three-phase systems:
- 0-20 Amp, 0-150 Amp, 0-500 Amp
Measures:
- Minimum, Maximum, and Average in Amp-RMS
- Current Accumulation in Amp-hours
Resolution: 0.1 - 0.3 Amp-RMS
Accuracy:
- Uncalibrated: ± 2% (typical)
- Calibrated: ± 1% (typical)
Configurable thresholds for critical condition monitoring
Industrial 150 Amp and 500 Amp options come standard with a detachable lead
Principles of Operation
ALTA Wireless Current Meters measure one or three AC RMS signals produced by current transformers (CTs). The analog current measurements are periodically converted to digital current measurements based on a user-configurable measurement interval. The meters report the minimum, maximum, and average current per CT, and the accumulated current over time at a user-configurable reporting interval or Heartbeat. On eve Heartbeat, the meter reports its recorded measurements to the gateway, making the data available in iMonnit or other approved data services.
ALTA Three-Phase Current Meters are only available in the Industrial version. Single-phase current meters can b calibrated for improved accuracy. Also, iMonnit can scale the accumulated current into kilowatt-hours for power monitoring.
Features of Monnit ALTA Sensors
Wireless range of 2,000+ feet through 18+ walls1
Frequency-Hopping Spread Spectrum (FHSS)
Best-in-class interference immunity
Best-in-class power management for longer battery life2
Encrypt-RF® Security (Diffie-Hellman Key Exchange + Advanced Encryption Standard (AES)-128 Cipher Block Chaining (CBC) for sensor data messages)
Sensor logs 2000 to 4000 readings if the gateway connection is lost (non-volatile flash, persists through power cycling):
10-minute Heartbeats = ~ 22 days
2-hour Heartbeats = ~ 266 days
Automatic over-the-air updates to sensor firmware (future-proof)
Free iMonnit Basic Online Wireless Sensor Monitoring and Notification System to configure sensors, view data, and send alerts via SMS text, email, and voice call
1 Actual range may vary depending on the environment and gateway.
2 Battery life is determined by the sensor reporting frequency and other variables. Other power options are also available
