This article is about UPS Static Switch Material Selection Criteria & Checklist & Requirements of Electrical Power System as per International Codes and standards for Commercial Buildings, Plants and Refinery Projects.
UPS Static Switch Material Selection Criteria & Checklist
QC Before Installation- Static Switch shall conform to all applicable requirements, standards, and specifications prior to release to be used as part of work.
Incoming Static Switch shall be visually inspected for damage / defects occurred during transportation and conformance to all applicable requirements..
Static Switch shall be new and unused.
Static Switch shall be in accordance with the Saudi Aramco-approved project-specific design drawings, diagrams, schedules, lists, databases, and associated design documents.
Check that the Contractor or it’s Saudi Aramco approved third party inspector performed the quality activities at the supplier and sub-supplier locations as required by the inspection level assigned for the materials and equipment identified in SAER-1972 Inspection Requirements.
Each UPS shall have a static bypass AC line switch for automatic transfers to the bypass AC line source.
A solid state make-before-break switch, rated for continuous operation at 125% of the UPS rated power shall be connected between the bypass and the load. A bypass static transfer switch consisting of a combination of SCR and contactor shall be acceptable for UPS systems greater than 500kVA only.
The inverter side static switch function may be integrated into the inverter’s IGBT switching devices provided that feedback power is prevented.
The solid state switch shall be a naturally commutated high speed type SCR type device.
The static switch shall transfer the UPS load to the bypass line when the transfer logic senses any of the following conditions.
“However, the transfer shall not be permitted unless the bypass AC line is in synch with the inverter and within normal specifications.
a) Inverter overload capacity exceeded.
b) UPS load over voltage or under voltage.
c) Battery low voltage disconnect activated.
d) UPS failure or “”out-of-limit”” condition.
e) Manual signal.”
The retransfer of power from the bypass line back to the inverter shall not occur until the inverter is in synchronization with the bypass line.
The AC line input shall have surge protection capable of absorbing voltage transients of a 4000 volt peak, 100 microsecond duration per IEC 62040-1 or 3.
The static switch shall be braced for the fault current of the bypass AC line transformer.
All internal devices and components shall be provided with an identifying number or a nameplate to identify the item and its function. Nameplate abbreviations shall match the item description shown on the UPS schematic drawings.
Check the performance requirement of Static Switch nameplate data.
Check that the UPS system are supplied from the approved manufacturer as per Regulated Vendors List for Electrical Equipment. (29 Feb. 2004 Issue) (09 June 2007 Issue)
“Instruction Manuals
Each system shall be provided with instruction manual(s) including the following information as a minimum. The required number of sets shall be as specified on the buyer’s Non-Material Requirements for Interruptible Power Supply (UPS) Form NMR-9597.
a) Installation & commissioning instructions
b) Operating instructions
c) Wiring & schematic diagrams
d) Service instructions with calibration & trouble shooting guide
e) Factory Test procedures & Certified test reports.
International Standard and Codes for UPS DC/AC Inverter Material
- Non-Hazardous Indoor Enclosures, Installation and Pre-Commissioning
- Boxes, Enclosures, and Accessories Materials Selection & Requirements
3. IEC-62040-1 or 3, UPS-General and Safety Requirements, June 2008
4. SAES-P-101 Regulated Vendors List for Electrical Equipment, 09 June 2007
5. 17-SAMSS-516 Uninterruptible Power Supply System, 13 August 2007