During the commissioning phase, this checklist provides a safe, consistent method for the initial inspection, checkout, testing, & data documentation of Uninterruptible Power Supply (UPS) & chargers.
The purpose of these tests is to verify that the board and all of its components are operating correctly. Typically, the batteries are recharged using the battery charger.
Additionally, the battery charger must supply DC power to the battery system. Le, the autonomy period in the case of a network outage, will be based on the battery capacity. Automatically supply uninterrupted power within the specified limits.
This procedure will make use of equipment drawings, schematic diagrams, and single line diagrams.
The equipment components listed below will be tested:
- Bridge battery charger using thyristors
- Static electronic switches
- Voltmeter and amperemeter control units
Essential Tools and Instruments
- Electronic multimeter
- Milliohm meter to test continuity
- 500Vdc mega ohmmeter
Preliminary Check (Initial Inspection)
- Verify the components of the battery charger board’s markings.
- Ensure that touching any equipment that is powered on while the system is in operation is not possible.
- Examine the auxiliary circuits (control, monitoring, alarm, and fault) and the main busbar for continuity.
- Check the continuity of the grounding busbar and its connection to the primary earthing system.
- Verify that earthing braids are used to connect the panel hinged doors to the frame.
- Door locks should be examined to ensure proper operation.
- Load circuit breakers and open all incomers.
- Verify that the connections match the tightness and reference drawings.
Electrical Inspections and Testing
Checking the continuity of all metal components with the ground. It is usually advised to utilize a milliohm meter for the continuity measurement when doing the test.
Insulation Resistance Test
In order to ensure that all isolating devices are opened, it is advised to carry out these checks prior to the connection starting.
Prior to conducting any tests, if wires are connected, open the isolating devices. Cut the control lines and the ground detecting device.
After a minute of electrification, check the insulation resistance with a 500 V DC mega ohmmeter between:
- Busbars with ground that are positive (+) and negative (-).
- Positive (+) busbar with ground and negative (-) busbar with it.
- Ground and the auxiliary circuit.
Test the cables and then reconnect them.
System Inspection
- Verification of manufacturer data
- Visual Inspection
- Proper device and cable labeling
- Adequate access to the device
- Unharmed device and cable
- Accurate termination of cables
- Sealing cable entrances in terminal boxes correctly
- Proper grounding and protective connections
- Appropriate power source
- Mechanical Inspection
- Establishing grounding connections
- Connections via cables
- Blocks at terminals
Electrical Function Testing
- Battery charger & battery/consumers are separated by open DC isolators.
- Turn on the primary supply voltage.
- Verify the phase sequence and voltage.
- Access the AC side of the battery charger.
- Verify the DC voltage in each mode of operation.
- Verify the DC isolator’s voltage & polarity on both sides.
- DC isolator to be closed.
- Verify annunciation
Battery Charger Panel Testing
- Attach the cables from the main distribution board, either the incoming ones or the battery supply and charger.
- Verify that there are mechanical protections in place to shield any unintentional contact with live parts. All outgoing disconnecting devices should be opened.
- Examine the alarm information return to the output terminal blocks on the distribution board.
Automatic Transfer Switches Testing
- Examine the electrical and/or mechanical interlocks.
- Verify the proper polarity.
- Check the functional checks for the existence of voltage, supply loss, and supply restoration in both manual and automatic modes using the two available supplies.
UPS Testing (Load Bank Test)
- If necessary, barriers or signs must be placed to make sure that anyone accessing the work area is aware of the activity that is going on.
- The load bank must be supported by cables that are sufficient in size to be run.
- Once it has been determined that the UPS is DEAD and safe to connect to, the final connection must be performed at the output point.
- After being turned on with no loads, the load bank will be functionally inspected. If all checks out, the UPS will be turned on and powered on to assist the load bank.
- If the load bank has a unity power factor, the load will be adjusted to the kW rating of the UPS, and it will be permitted to run for 15 minutes.
- To mimic a mains failure, the nearest isolation point upward of the UPS will experience a mains failure upon initiating the battery discharge test.
- Until the cut-off voltage is reached, the UPS display will record the battery voltage & current every 60 seconds.
- Reinstalling the main supply and allowing the UPS to restart are required. The battery may be recharged, and the voltage and current during the process must be noted.
- The load bank must be switched off and allowed to cool down before being disconnected. To enable the disconnect of the load bank, the UPS’s output will be isolated.
- After the load bank test is finished, all power and control connections need to be made again and thoroughly inspected.
- The UPS will be turned on and left to recharge, either by providing the load or isolating it, if the battery still needs to be charged.
