March 2016 Newsletter: I’m Truckin’ ALS Challenge
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When things are good for us, they get better for our customers, and 2016 has been very good to us.
We want to show our appreciation for all of the support our partners and friends have given us, so we’re leading the charge with the “I’m Truckin’ ALS Challenge”.
Through July 15th, 2016, we’ll provide FREE UPS GROUND shipping for any controller (and parts on the same order) shipment in the continental USA (lower 48).
Along with that, we will donate $5 to ALS for each controller shipment through July 15th, 2016. This charity is near and dear to our hearts, so everybody wins. We hope other providers take up the “I’m Truckin’ ALS Challenge” as well.
You can also donate to ALS directly anytime at : ALS of Wisconsin (Ref in memorium of Sheila Salsman
Note: Only orders that includes a new controller will receive the free UPS Ground shipping. The UPS ground cost credit cannot be used or applied to priority shipments. Spare part, accessory only and replacement part only non-controller orders are not included in this promotion. Lakewood reserves the right to extend, end, or alter this promotion at any time.
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AWT.ORG Training in Indianapolis April 13-17
Training benefits every employee. Training provided by “Industry experienced” instructors that have a working knowledge of the processes, is doubly beneficial. That’s what attendees to the AWT.org annual trainings get.
There is another one coming up in Indianapolis in April. Are your technicians and field service team ready to step up their game and get the kind of information and interaction that benefits the entire company? (The correct answer is YES!!)
More experienced team members can enhance the company profile (and benefit their customers) by attaining their CWT (Certified Water Technologist) from the AWT. The first step is to attend the classes offered to determine which one(s) best fulfill the needs of your organization.
by Paul Peacock
Recently, I spoke with a customer that had an issue with a few model 140 controllers, where the conductivity sensor’s graphite tips were gone. We ruled out breakage as both tips were missing. They were actually down inside of the sensor bodies and there were no debris in the plumbing assemblies. Those were the same symptoms on each of the controllers.
During our troubleshooting, we determined that the customer was using the 4-20 mA outputs to send the conductivity readings to a building automation system (BAS). They were also having our controller power the loop. We performed a voltage check between the controller and the BAS and found about 0.4 VDC between the BMS wire and the model 140 ground terminal (P2, pin 1) of the 4-20 mA output. This is indicative of a ground loop between the controller and the BAS. Their input was NOT isolated from ground, which is required when we power the loop.
A ground loop is a condition where an unintended connection to ground is made through an electrical conductor. Generally, a ground loop connection can exist when an electrical system is connected to the electrical ground through more than one pathway. The different pathways can cause a voltage to be developed when the two electrical grounds are at different potentials. Ground loops can cause all kinds of issues with controllers from erratic readings, to damaged sensors, or even damaged electronics.
In the case of the above model 140 (or model 150, or 1575e) controllers, the ground loop applied a voltage to the instrument ground of the controllers, which in turn applied this voltage across the conductivity sensor tips and ate them away.
To check for a ground loop when the 4-20 mA output of a Lakewood controller is involved, disconnect the wire from terminal 1 of the P2 terminal block, labeled GND on the board and use a voltmeter to check for both AC and DC voltages between the wire to the BAS and terminal 1 of the P2 terminal block of the 4-20 mA output. There should be less than 0.1 volts, anything more, and there needs to be additional isolation provided.
There are two methods we recommend to correct ground loops in the 4-20 mA circuits, if we must power the loop. The first is to use an verified isolated input on the BAS end of the connection. With everything powered up, you can use the test above to verify the connection is isolated. The second is to use a isolation transformer. All of the Lakewood Instruments controllers have the ability to be wired as an isolated (BAS provides loop power) or a non-isolated output (We provide loop power). Lakewood Instruments also offers an isolation kit to prevent ground loops.
Please, as always, feel free to contact your friendly Lakewood Instruments technician for assistance in finding and correcting ground loops!