There are two suggested methods of using the DVLD to protect remote site equipment. One method follows the lines of a “hands-off” philosophy and the other is more of a “hands-on” method. You may obviously decide to adapt these suggestions to your particular operational needs.
Hands-off setup
In this philosophy of operation, you set the Distance Trigger to a value that you think will be at the limit for safe operation of your site (say 5 or 10 km). Once a reading has breached this distance, the Davicom is configured to automatically take action at the site and shut things down. This can be done by passing the LD01 flag through a Virtual Logic Gate (VLG) and controlling a relay as shown in the screen shot below.
For DV-Mini or DV-2-8/216 units, the control could also take the form of sending an SNMP trap or performing an SNMP SET.
If you wish, the Davicom can also be configured to send an alarm when the Distance Trigger event occurs, in addition to the local control commands. The example below shows an e-mail address configured as an alarm destination.
Hands on setup
In this philosophy of operation, you set a threshold to give you a “heads-up” minor alarm so you can “track” the incoming storm and then decide what action you wish to take (yourself, manually) when a certain closer threshold is reached.
To achieve this dual-threshold capability, it is necessary to use the Metering Math Functions built-in to the Davicom units. The MMF’s have two-level alarm capability built-in. The example below shows that a Minor Alarm has been set for a minimum distance of 30 km and a Major Alarm has been set for a minimum of 10 km. Note the * in the “High” field, indicating a “don’t care” condition.
This Metering Math Function feature only works with firmware 5.56.17355 or more recent.
Logging
The DVLD and Davicom units can also be used to log lightning storm activity in the vicinity of your site. The data can be transferred at periodic intervals and compiled in Excel to produce a chart of storm activity and proximity to the site. The figure below shows the DVLD range data of a real thunderstorm that passed right over our offices in the evening on June 18th 2015.
To achieve this functionality, the custom-log and data logging features must be used.
Firstly, the « Custom Log » box must be checked as shown below.
Then, the Custom Log can be configured as shown below to transfer the log by e-mail when it reaches 90% capacity. The Data logging must be activated to take periodic samples (every 5 minutes in this example). This will give about 288 samples per day and should produce an email every 3 or 4 days.
