Latching AC Power Failure Detector for Sensatronics Temperature Monitors. Quick Start Guide

Transcription

1 Latching AC Power Failure Detector for Sensatronics Temperature Monitors Quick Start Guide Overview: This accessory for the TempElert software (standard and Spectrum versions) is designed to connect to a Sensatronics model E4, E8, E16 or U16 remote temperature logging device to give an indication of an AC power failure that can be sensed. The unit is designed to detect short duration power failures of ~ 250 milliseconds as well as long duration power failures. The accessory is designed to plug into a 120VAC electrical outlet and the optically isolated (for safety) signal for power failure is carried through a twisted pair wire to the one of the channel terminals of Sensatronics monitoring device. The TempElert software can be configured to detect this channel as a switch closure, where normally closed means the AC power is OK and an open condition would indicate an AC power failure had occurred. Unpacking: The power failure detector accessory consists of four single items. 1. The USB 120VAC wall power supply unit 2. The power failure detector unit with pushbutton switch and LED 3. USB A male to B male adapter plug 4. Length of twisted pair wire

2 Assembly and Testing Instructions: 1. Connect the USB power supply to the detector using an A male to B male adaptor or cable (see alternate wiring connections for cable description). 2. Using the twisted pair wire provided, connect the Sensatronics device to the detector unit. For ease of installation, the green terminal plug can be removed from the detector unit if need be. See photo below for the detector unit. Detector unit with twisted pair wire installed NOTE: this is a polarity sensitive connection, and if wires are reversed, the unit will not properly signal the Sensatronics device. Connect a Sensatronics unit channel as follows: a. Pin C (orange) connects to the left contact of the sensor connector pair on the Sensatronics device and also on the detector. b. Pin E (yellow) connects to right contact of the sensor connector pair on the Sensatronics device and also on the detector. See the photo below for the wiring connection to terminals on the Sensatronics unit. Twisted pair wire connected to Sensatronics unit 3. Plug the USB power adapter into the AC outlet you wish to monitor. See photo below for an assembled example. Note that the colors on the cable in this example photo don t matter, only the orientation of the connection between the detector and the Sensatronics unit

3 Fully assembled detector system before arming 4. The LED on the detector should be dark as shown in the photo above. 5. Setup the TempElert software so that the probe channel you connected to the detector is defined as a switch. Setup the probe channel to alarm when the switch is open. 6. Check the display of TempElert, the probe should indicate that the switch is open and in an alarm state. 7. Press the black button on the detector. The LED should light indicating that the power is good and that the detector is armed. See the photo below. Detector is armed when the green LED is on. 8. Check the display of the TempElert software, the probe should indicate that the switch is closed and is in a normal state. 9. Unplug the USB power supply and plug it back in. The LED should become dark and TempElert will (after the Device Query Interval) indicate an alarm on the probe. NOTE: if this test fails to show on the TempElert software, you may have the wires between the detector and the Sensatronics unit reversed, or you may not have setup the probe channel properly. Double check each and if need be reverse the wires. Continue checking and testing until you get a proper alarm indication on the TempElert software. 10. Press the black button to re-arm the detector. 11. Setup is complete.

4 12. In the case of a power failure, the green LED will go dark, and a press of the black button is required to reset the detector to the armed state. Alternate wiring connections If for some reason you cannot connect the detector unit and the USB power supply as shown above using the USB adaptor plug (due to space or location constraints) you can connect the two using a length of USB adaptor cable as shown below. A USB extender cable can also be used to connect the power supply and detector For remote connections You can also use a length of twisted pair wire of almost any gauge and lengths of up to ~ 200 feet to connect between the detector and Sensatronics unit. Theoretically, lengths of up to 1000 feet may work but this has not been tested. However, long runs of such cable maybe prone to spurious interference from induced power spikes into the wire from electrical equipment. Running such cable in a grounded conduit for very long lengths is desirable. Optical isolation For safety, the power failure detector is electrically isolated between the AC power supply and the Sensatronics device so that spurious power surges and/or lightning induced surges won t connect with sensitive computer equipment. For those familiar with such techniques, the diagram below shows the output of the detector as it is presented to the terminals.

5 The 4N37 opto-isolator chip in the detector has an optically activated transistor which is used to signal the Sensatronics device of a power failure condition. Normally, when the detector is armed (green LED ON) the 4N37 opto-isolator is also turned on, providing an always on circuit path from collector C to the emitter E as show in the diagram above. An interruption of the AC power breaks this circuit, turns off the LED, and signals the Sensatronics unit of a power failure condition, even if the AC power is restored. The characteristics of the 4N37 opto-isolation chip are shown below: The detector unit uses the white package, providing an isolation of 7500 volts. Troubleshooting 1. The USB power supply LED is not on - check the AC outlet to be sure the circuit breaker is ON. 2. Power failure test fails to show on the TempElert software - you may have the wires between the detector and the Sensatronics unit reversed or the wire may not be properly inserted into one or more of the terminals. Be sure to use a screwdriver to secure the terminal wires firmly. 3. The Green LED on the detector refuses to turn on when the black arming button is pressed see item 1, and also check to be sure the connector and cable between the USB power supply and the detector unit is fully plugged in and secure. For service contact: ItWorks 3008 Cohasset Road Chico, CA info@itworks.com