Here are some words and pictures from our recent swap of the batteries in the UPS unit connected to our 800's BMPC-II cabinet. Posted August 8th, 2013 - John Harwood.
A few weeks ago we bit the bullet and swapped out all sixty(!) of the batteries in the UPS unit and the battery extension cabinet. On our 800 we have a Victron L6-11 UPS along with an extension cabinet made by a different company. Our batteries had never been changed and the unit failed its "deep battery calibration test" when it was performed a few months ago. As a precautionary measure we also replaced the cooling fan in the Victron cabinet at the same time. During this work we kept the BMPC-II cabinet running using the Victron's bypass mode, as described under "Procedure B" in Chapter 3 of the Victron manual. In the end it turned out that the process was reasonably straight-forward, it took Jerry Hirschinger and I approximately four hours to complete the entire job. However, a couple of weeks prior to starting the job we did practice switching the UPS to bypass mode and shutting it down, as well as taking its cabinet panels off, so we knew a little bit about what to expect. Below are some comments based on our experience with our own equipment, followed by a few pictures. Please note that these comments are for general informational purposes only and are not intended to replace the reading and understanding of the unit's service manual.
Comments and Notes
- Do not attempt this work unless you are thoroughly experienced at working on live electrical equipment. In bypass mode there is still mains power present in parts of the UPS cabinet and the batteries also have voltage present. Also, there should always be two people present when working on this equipment.
- We would recommend powering down the NMR console prior to putting the UPS into bypass mode. In our installation the UPS acts as a boost transformer in addition to its UPS duties. Going into bypass mode on our equipment generated error messages from the console's BSMS unit so the spectrometer could not be used anyway.
- Our Victron UPS cabinet uses different batteries from those used in our battery extension cabinet. Our Victron uses twenty 12-volt, 7.2-amp/hr batteries and the extension uses forty 12-volt, 12-amp/hr batteries, which have different dimensions. We would recommend checking your existing batteries prior to ordering new ones.
- After going into bypass mode and then shutting off the UPS unit, you will need to wait ca. 20 minutes before commencing work inside the unit. Wait until the voltage present on the terminals of the large capacitor (shown in the picture labeled "ups-5") is less than 3 volts.
- Our UPS unit had three large ceramic fuses inside, shown in picture "ups-6." One of these fuses was labeled differently than what was shown in the schematics and discussion in the Victron manual. However, after tracing the wiring we determined that removing all three fuses would accomplish the circuit disconnections necessary prior to changing the batteries. For example, the fuse labeled F2 in our unit appeared to be the same as that labeled F7 in the manual, and we removed fuse F3 instead of disconnecting connector PP45 as described in the manual.
- In our extension cabinet, the clamp which holds the batteries in place on the lower three out of four rows is part of the battery shelf above it. Therefore one will need to remove the uppermost clamps (2) and batteries (10) first, then the next clamp/shelf set (2) followed by the next set of batteries (10), and so on working from top to bottom. The general layout of our extension cabinet is shown in picture "ups-9" and the clamp/shelf pieces are the three black metal pieces shown adjacent to the batteries in picture "ups-11."
- On our extension unit the clamp/shelf combination pieces were mounted using two screws in the middle of the unit along with four screws at each end of the unit. These end screws are the three horizontal rows of screws shown in picture "ups-13."
- In order to remove the screws located in the center of the unit holding the battery clamps (Victron) and clamp/shelf units (extension) in place, a Phillips screwdriver with at least a 6"-long shaft will be needed. To help prevent the possibility of contacting the battery terminals when using the screwdriver close to them, we laid cardboard sheets on top of the batteries as shown in picture "ups-8."
- The Victron manual indicated that our unit should have two cooling fans, a big one and a small one, however, our unit only had the big one (picture "ups-3").
- One day after completing the battery replacement I attempted the "deep battery calibration test." With a load of 42% the test ran for over two hours and completed successfully. A couple of days after that we had occasion to shut down the power to the BMPC unit, and with the BMPC unit alone (i.e. no NMR console) running on the UPS the UPS display indicated that the backup power would last for 7 hrs 45 min.
- For completeness I mention the following. (1)The Victron manual recommends carrying out the "deep battery calibration test" at approximately 6-month intervals. (2)The manual indicates that the UPS battery life is expected to be 3 to 6 years. (3)The manual suggests the operational life of the cooling fan(s) to be 2 to 4.5 years.
Pictures
