We previously discussed what you should look for when reviewing a proper service contract for emergency back-up power systems maintenance. When you hire a qualified firm to perform maintenance inspections on your equipment, you need to have total confidence in that firm’s level of knowledge and level of execution of inspection and testing. But how do you know what is most important to look for when that firm shows up at your office, ready to perform maintenance? We will briefly discuss what you should be looking for, and also what to watch out for with these inspections. Please be aware that this is an abbreviated list and should not be considered comprehensive.
A routine maintenance inspection for your Uninterruptible Power System (UPS) should start with the following:
- Technician is wearing proper Personal Protective Equipment (PPE)
- Proper adherence to Statement of Work (SOW)
- Proper impedance testing and trending of batteries
The technician will likely perform numerous tests during inspection to prove the integrity and safety of the equipment being used. There are several top priorities technicians typically have for performing preventative maintenance on a static UPS.
What are the most important things to check for during a routine maintenance inspection of a UPS?
- Full functionality of the UPS to include bypass operations
- Power Control Board (PCB) thermal inspection
- Capacitor, Silicon Controlled Rectifier (SCR), Insulated Gate Bipolar Transistor (IGBT) and other components integrity
- Battery testing
- A simulation of a power outage to prove functionality
When dealing with maintenance, it’s always important for your technician to be well prepared for potential issues during the inspection process and to be prepared to address them. Here are some typical things to look out for and some general solutions.
What are some possible red flags during the maintenance and testing process and how should they be resolved?
Issue: During thermography scanning, hot spots on connections can be detected, or the technician identifies PCBs or contractors and loose connections.
- Solution: The UPS may need to be shut down in this case at a convenient time and torqued to specifications, or components must be replaced if they are worn or loose.
Issue: Event log shows nominal data entries and events that are non-standard.
- Solution: These log entries can help determine if there is an underlying issue with the UPS and possibly predict failures before they happen.
Issue: UPS may have an alarm, or may sound loud or different than normal.
- Solution: A UPS system has numerous components, including fans, relays and contactors that can fail or pose future problems. A preventative maintenance inspection should help to identify these failing components before a problem occurs.
Issue: Upon inspection, battery has failed testing and may be swollen or cracked.
- Solution: Preventative maintenance on UPS batteries helps to identify batteries that are trending poorly. There are a few main issues when it comes to UPS System batteries. The largest contributors to premature battery failure in a UPS are high ambient temperatures and improper charging current. In fact, for every 15 degrees above 77F, a batteries life expectancy is reduced by about 50%. It must first be verified that operation of the charging current is working properly. If the battery itself is old, the string of batteries typically should be replaced in totality. If the battery is new, you may be able to replace individual batteries as one may have been damaged in shipping or have a manufacturing defect.
You should also make certain that your provider has a comprehensive scope of work in place for all major and minor PM inspections and that you both agree to the provisions in the scope of work before any work is done. Contact QPS and we can help you better understand what you should look for in a PM and a comprehensive scope of work.