10-14 B90 LOW IMPEDANCE BUS DIFFERENTIAL SYSTEM – INSTRUCTION MANUALBATTERY CHAPTER 10: MAINTENANCE1010.9 BatteryA battery powers the real time clock on startup of the device.When required, the battery can be replaced. The power supply module contains the battery. The battery type is 3 Vcylindrical.10.9.1 Replace battery for SH/SL power supplyWhen required, the battery can be replaced. The power supply module contains the battery.To replace the battery:1. Turn off the power to the unit.2. Wait a minimum of three minutes to ensure that there is no power to the battery.3. As outlined in the previous section, open the unit by sliding up the plastic latch on the right side of the front panel(standard front panel) or unscrewing the panel (enhanced front panel).4. For the standard front panel, it needs to be removed in order to access the power supply module, which is typically inthe first slot on the left side and blocked by the hinge of the front panel. To remove the front panel, unscrew the bracketon the left side of the unit.5. Remove the power supply module by simultaneously pulling the ejector clips at the top and bottom of the module andsliding it out.6. Unscrew all four screws (not three) that attach the metal cover to the module. The fourth screw is at the back end ofthe module, on the opposite side from the clips, beside the white electronics part (see figure).7. Slide the metal cover away from the clips about 0.5 cm (1/8 inch) and remove the cover.8. Unclip the black plastic holder that keeps the battery in place. The plastic clips into the socket at the bottom on bothsides—pull the plastic away from the battery. Use a flat-head screwdriver if you cannot unclip the plastic with yourfingers.9. Replace the battery with the identical make and model. For example, do not use a rechargeable battery. Observe the+ and - polarity of the battery and replace it with the same polarity as marked on the battery holder.When adding a module (versus replacing a module), check that settings have not changed. Depending on themodule, settings can reset to default values.The new CT/VT modules can only be used with new CPUs; similarly, old CT/VT modules can only be used with oldCPUs. In the event that there is a mismatch between the CPU and CT/VT module, the relay does not function and aDSP ERROR or HARDWARE MISMATCH error displays.To avoid injury, ensure that the unit has been powered off for a minimum of three minutes beforereplacing the battery.Risk of fire if battery is replaced with incorrect type or polarity.
