LVM-250 Isolated Line Voltage Monitor

Transcription

1 LVM-250 Isolated Line Voltage Monitor The LVM-250 is designed to measure 2-wire single phase 50/60Hz line voltage up to 250 VAC. It is used in conjunction with the ecna automation to monitor the power line for voltage sags or a complete voltage loss. The LVM-250 sends the measured RMS voltage to the ecna via the LIN serial link. The ecna monitors this voltage and based on user defined parameters generate events that can be used to pause and re-start the SMS in the event of an under voltage condition. Figure 1: Voltage Monitor Connection The voltage monitor board is powered by the LIN. It continuously sends the RMS voltage values to the ecna via the LIN serial communications. Figure 2: Voltage Monitor Board 1

2 LVM-250 Line Voltage Monitor Setup and Operation The LVM-250 is calibrated at the factory. No further adjustments are required. Connect the LVM-250 to the ecna LIN and to the line side of the UPS (Uninterruptible Power Supply) with the supplied cables (See Figure 1). Power up the ecna and navigate to the Local I/O Network status screen to view the Voltage Monitor status screen. The RMS Voltage is displayed on the Inputs section of the screen. The Inputs field displays the actual measured line voltage. It is a running average of the measured RMS value. This value will help to determine the best Lower and Upper Threshold values. Now navigate to the LVM-250 Voltage Monitor setup screen. This screen is used to configure the LVM-250 Voltage Monitor control parameters. Parameter Name Symbol Definition Lower Voltage Threshold Upper Voltage Threshold Voltage Low Event Hold-Off Time Voltage Low Window Time Voltage OK Event Hold-Off Time Voltage Logging Period V TL V TU T VLH Establishes the low voltage trip point. Range = 0 to 250 volts Establishes the upper voltage okay point. Range = 0 to 250 volts Sets the delay from the line voltage not okay condition to the Line Voltage Low Event. Range = 0:00 to 59:59 mm:ss T Establishes a time period where the Voltage OK 1 Event can occur. Range = 0:00 to 59:59 VLW mm:ss T VOH Sets the delay from the from the line voltage okay condition to the Line Voltage OK 1 and OK 2 Events. Range = 0:00 to 59:59 mm:ss Sets the Voltage Logging interval. Range = 0:00 to 59:59 mm:ss. 0:00 disables logging. 2

3 Events These three Line Voltage events can be assigned to triggers. Line Voltage Low - This event occurs when the line voltage goes below the Lower Voltage Threshold, V T L for a time greater than the Voltage Low Event Hold-Off Time, T. V LH Line Voltage OK 1 - This event can only occur inside the Voltage Low Window. This event occurs when the line voltage returns to the okay condition and remains okay for a time greater than the Voltage OK Event Hold-Off Time, T. V O H Line Voltage OK 2 - This event can only occur outside the Voltage Low Window. This event occurs when the line voltage returns to the okay condition and remains okay for a time greater than the Voltage OK Event Hold-Off Time, T. V O H Figure 3 This diagram illustrates how the Line Voltage events can be generated. The red line represents the line voltage. When the voltage drops below the Lower Voltage Threshold, V T L, the Voltage Low Hold-off, T V LH, and the Voltage Low Window, T V LW, timers start to tick. If the Voltage Low Hold-off timer, T V LH, is allowed to expire, the Line Voltage Low Event is generated. If the voltage goes above the Upper Voltage Threshold, V TU, before the Voltage Low Window timer, T V LW, expires, the Voltage Okay Hold-off timer, T V O H, starts to tick. If this timer is allowed to expire, the Line Voltage OK 1 Event is generated. If the voltage goes above the Upper Voltage Threshold, V T U, after the Voltage Low Window timer, T V LW, expires, the Voltage Okay Hold-off timer, T V O H, starts to tick. If this timer is allowed to expire, the Line Voltage OK 2 Event is generated. 1. The Voltage Low Hold-off timer, T V LH, is reset if the voltage goes above the Upper Voltage Threshold, V T U and the Line Voltage Low event will not be generated. 2. The Voltage Okay Hold-off timer, T V O H, is reset if the voltage falls below the Lower Voltage Threshold, V T L, and the Line Voltage OK 1 or the Line Voltage OK 2 event will not be generated. 3. The Voltage Low Window timer, T, is reset if the voltage goes above the Upper Voltage Threshold, V. V LW T U Application The Line Voltage Low Event can be used to automatically and systematically shut down the equipment and notify theatre personnel of a power problem. The Line Voltage OK 1 Event can be used to automatically recover from a low voltage condition, such as resuming the movie. The Line Voltage OK 2 Event can be used to take appropriate action when the voltage is restored. The following two examples demonstrate how the voltage monitor can be used. The macros and triggers can be added to an existing application. 3

4 Example 1 In this example, a 10 second timer starts when the line voltage drops below 185 volts. If the voltage goes above 190 volts before the timer reaches 10 seconds, the timer is reset and the SMS will continue to play. If the timer expires, the SMS will be paused. LVM-250 Settings: Lower Voltage Threshold = 185 Volts Upper Voltage Threshold = 190 Volts Voltage Low Event Hold-Off Time = 10 seconds Voltage Low Window Time = 0 seconds Voltage OK Event Hold-Off Time = 0 seconds Trigger Assignments: The following trigger assignments are used in this example. Name Controlled by Calls Macro Line Fault Line Voltage Low 9: SMS Pause/Stop Macro: The SMS Pause/Stop macro (macro 9) is called when the Line Voltage Low event pauses the SMS. 9: SMS Pause/Stop Projector Digital 1 Vid Off 00:00 Pause/Stop the SMS There is a caveat to the example above. If the power comes and goes after the SMS has been paused, the RPT,EVT,0,DV1OFF,... message may be sent again and again to the SMS. This shouldn t be a problem, but it can be prevented by using a control flag and the Exit If instruction. In the example below, the Aux Out 16 output control flag is used as the Voltage Monitoring (VM) control flag. If the voltage returns to the okay condition, the VM flag is set. When this flag is set (On), the Digital 1 Vid Off instruction is skipped and the RPT,EVT,0,DV1OFF,... message is not sent again. The flag must be cleared so the ecna is ready to sense the next power outage. This should happen on a start or resume by setting Aux Out 16 = Off with an output command or a macro. New Trigger Assignment: Name Controlled by Calls Macro Set VM Flag Line Voltage OK 2 10: Set VM Flag Macros: The SMS Pause/Stop macro is modified with the Exit If instruction. The macro is called when the Line Voltage Low event pauses the SMS only if the Voltage Monitoring (VM) flag is cleared. 9: SMS Pause/Stop Exit If Out 16 On 00:00 Projector Digital 1 Vid Off 00:00 Pause/Stop the SMS The Set VM Flag macro sets the Voltage Monitoring (VM) flag to prevent an unwanted pause message. 10: Set VM Flag Exit If Out 16 On 00:00 Set VM Flag 4

5 Example 2 In this example, a 10 second timer starts when the line voltage drops below 185 volts. If the voltage goes above 185 volts before the timer reaches 10 seconds, the timer is reset and the SMS will continue to play. If the timer expires, the SMS will be paused. If the voltage is restored before 1 minute, the SMS is restarted if the voltage is okay for 5 seconds. If the voltage is restored after 1 minute, the SMS remains paused. The Aux Out 16 output control flag is used as the Voltage Monitoring (VM) control flag. If the voltage returns to the okay condition after 1 minute, the VM flag is set. This prevents the SMS from restarting if the voltage is restored. The flag must be cleared so the ecna is ready to sense the next power outage. This should happen on a start or resume by setting Aux Out 16 = Off with an output command or a macro. LVM-250 Settings: Lower Voltage Threshold = 185 Volts Upper Voltage Threshold = 190 Volts Voltage Low Event Hold-Off Time = 10 seconds Voltage Low Window Time = 1 minute Voltage OK Event Hold-Off Time = 5 seconds Trigger Assignments: The following trigger assignments are used in this example. Name Controlled by Calls Macro Line Fault Line Voltage Low 9: SMS Pause/Stop Set VM Flag Line Voltage OK 2 10: Set VM Flag Line Okay Line Voltage OK 1 11: SMS Strt/Resum Macros: The SMS Pause/Stop macro (macro 9) is called when the Line Voltage Low event pauses the SMS only if the Voltage Monitoring (VM) flag is cleared. 9: SMS Pause/Stop Exit If Out 16 On 00:00 Projector Digital 1 Vid Off 00:00 Pause/Stop the SMS The Set VM Flag macro (macro 10) sets the Voltage Monitoring (VM) flag. 10: Set VM Flag Exit If Out 16 On 00:00 Set VM Flag The SMS Strt/Resum macro (macro 11) resumes the SMS only if the Voltage Monitoring (VM) flag is cleared. 11: SMS Strt/Resum Exit If Out 16 On 00:00 Projector Digital 1 Vid On 00:00 Resume the SMS Aux Out 16 Off 00:00 Clear the VM flag 5

6 Voltage Logging The ecna-10 can log line voltage data collected from the LVM-250 Line Voltage Monitor. The VoltHiLo Event (#105) contains the highest and lowest line voltage values collected since the last logged VoltHiLo event. The Voltage Logging Period parameter on the LVM-250 Voltage Monitor setup screen sets the logging interval. The range is 0:00 to 59:59 in minutes and seconds. 0:00 suppresses logging of the event. Logging the line voltage can be helpful in detecting problems, such as voltage sags, surges, brownouts or total failure of utility power that can cause problems with or even damage the cinema equipment. Just for fun, the following graph was created with both high and low line voltage plotted over a 15 minute period. The voltage was collected every second. The graph was created in an Excel Worksheet with imported VoltHiLo Event records. 6