Reference: SOP-MAINT-SVR-UPS-001

Creation Date: 2025-04-01

Revision Date: To be defined (schedule an annual review or according to
manufacturer's recommendations)

1. Objective:
To describe the steps to follow for performing preventive and corrective
maintenance on industrial Voltage Stabilizer (SVR) and Uninterruptible Power Supply
(UPS) panels to ensure a stable and continuous power supply to critical equipment.

2. Scope of Application:
This procedure applies to all electrical maintenance technicians and UPS/SVR
specialists authorized to work on these equipment.

3. Responsibilities:
* Electrical Maintenance Supervisor: Responsible for planning, supervising, and
approving maintenance work.
* Electrical Maintenance Technician/UPS/SVR Specialist: Responsible for executing
maintenance tasks in accordance with this procedure and safety instructions, and
according to manufacturer's specifications.

4. Definitions:
* SVR: Voltage Stabilizer (Automatic Voltage Regulator - AVR). Device that
maintains a stable output voltage despite variations in the input voltage.
* UPS: Uninterruptible Power Supply. Device that provides backup power in the event
of a power outage.
* Battery: Energy storage element used in UPS systems.
* Bypass: Alternative circuit allowing the load to be powered directly from the
main source, bypassing the UPS or SVR.

5. Required Materials and Equipment:

* Appropriate PPE for electrical work: Safety helmet, safety glasses, insulating
gloves (class appropriate to the voltage), insulating safety shoes.
* Voltage tester (VAT) certified and calibrated.
* Digital multimeter certified and calibrated.
* Clamp meter.
* Infrared thermometer.
* Hydrometer or battery tester (if lead-acid batteries).
* Specific UPS battery tester (if available).
* UPS/SVR monitoring software (if applicable).
* Appropriate wrenches and tools for tightening connections.
* Specific cleaning products for electrical equipment.
* Lint-free cloths.
* Technical documentation of SVR and UPS (manufacturer's manuals).
* Work permit (if required by company policy).

6. Preventive Maintenance Procedure:

6.1. Preparation:
a. Plan maintenance in coordination with concerned teams to minimize
interruptions.
b. Obtain necessary work permits.
c. Gather necessary materials, equipment, and documentation.
d. Ensure the maintenance team is qualified and trained on the specific
equipment.
e. Perform a risk analysis and identify specific safety measures.
f. Prepare the work area, ensuring it is clean and clear.

6.2. Lockout/Tagout (if necessary):

 a. If maintenance requires complete power down, follow the company's
lockout/tagout procedure. For UPS systems, this may involve switching to bypass
mode and disconnecting the main power and batteries.
b. Verify the absence of voltage before starting any internal work.

6.3. Visual Inspection (SVR and UPS):

a. Inspect the exterior of the panels for any signs of physical damage,
corrosion, overheating (discoloration), cracks, or deformations.
b. Check the condition of seals and cooling systems (fans, heat exchangers).
c. Ensure status indicators and alarms are functional.
d. Verify the general cleanliness inside and outside the panels.
e. Inspect visible wiring for signs of damage, loosening, or overheating.

6.4. Cleaning (SVR and UPS):

a. Clean the interior and exterior of the panels carefully with specific
cleaning products for electrical equipment and lint-free cloths.
b. Remove dust and contaminants that can affect cooling and electronic
performance.

6.5. Connection Verification (SVR and UPS):

a. Verify the tightness of all electrical connections (power terminals, output
terminals, battery connections, control and signaling terminals) using appropriate
tools and referring to the recommended torque values.
b. Look for signs of corrosion or oxidation and clean them if necessary. Apply a
protective product if recommended.

6.6. Maintenance of Voltage Stabilizer (SVR):

a. Verify the proper functioning of the voltage regulation system by measuring
input and output voltage under different loads (if possible and safe).
b. Inspect internal components (transformers, thyristors, etc.) for signs of
overheating or damage.
c. Verify the operation of protection circuits (overvoltage, undervoltage).

6.7. Maintenance of Uninterruptible Power Supply (UPS):

a. **Batteries:**
i. Visually inspect batteries for cracks, leaks, or swelling.
ii. Check the cleanliness of terminals and connections. Clean if necessary
and apply a terminal protector.
iii. Measure the voltage of each battery and the entire battery bank. Compare
to specified values.
iv. If lead-acid batteries, check the electrolyte level and specific gravity
with a hydrometer (if applicable). Replenish if necessary with distilled water
only.
v. Perform a battery discharge test according to the manufacturer's
recommendations to evaluate their capacity and autonomy.
vi. Verify the proper functioning of the battery charging system.
b. **Power Electronics:**
i. Inspect capacitors, inductors, transistors, and other components for signs
of overheating, damage, or leakage.
ii. Verify the proper functioning of cooling fans.
c. **Bypass:**
i. Verify the proper functioning of the bypass circuit (automatic and
manual).
d. **Software and Alarms:**
i. Verify the proper functioning of the monitoring software (if installed).
ii. Test the alarms (low battery, overload, fault, etc.).

6.8. Ventilation and Temperature Control Verification (SVR and UPS):

a. Ensure ventilation grilles are not obstructed.
 b. Verify the operation of fans and cooling systems.
c. Measure the temperature inside the panels and compare it to normal values.

6.9. Reconnection and Post-Maintenance Testing:

a. Verify that all tools, materials, and personnel are out of the panels.
b. Remove lockout padlocks and tags (if applied).
c. Perform a final inspection to ensure everything is in order.
d. Re-energize the SVR and UPS following the energizing procedure.
e. Verify the proper operation of the equipment under load. Monitor voltages,
currents, and alarms.
f. Simulate a power outage to test the UPS operation on battery and the return
to main power.

6.10. Documentation:
a. Record all observations, measurements taken, work performed, and parts
replaced in a maintenance log or CMMS.
b. Record battery test results and configuration parameters.
c. Report any anomalies or non-conformities and the corrective actions taken.
d. Update the equipment's maintenance history.

7. Corrective Maintenance Procedure:

a. Identify the problem (UPS failure, unstable output voltage from SVR, battery
alarm, etc.).
b. Safety: Isolate the defective equipment if necessary (switch to bypass if
possible for UPS).
c. Diagnose the cause of the failure by consulting technical documentation and
performing appropriate tests.
d. Repair or Replacement: Perform necessary repairs (replace defective
batteries, damaged electronic components). Use compatible and quality spare parts.
e. Post-Repair Testing: Perform necessary tests to ensure the problem is
resolved and the equipment operates correctly and safely. Especially test the UPS
autonomy after a battery replacement.
f. Re-energizing: Follow the energizing procedure.
g. Documentation: Document in detail the nature of the failure, the corrective
actions taken, and the parts replaced.

8. Specific Safety Measures for Work on SVR and UPS:

* Work on SVR and UPS must be performed by qualified and trained personnel on
these types of equipment.
* Wearing appropriate PPE is mandatory.
* Pay particular attention to the risks associated with batteries (short
circuit, handling of electrolyte).
* Respect the specific power down and lockout/tagout procedures for UPS systems
(battery disconnection).
* Ensure the load connected to the UPS does not exceed its rated capacity.
* Always consult the manufacturer's documentation before performing any
intervention.