With reference to UPS (Uninterruptible Power Supply) systems in industrial automation:1.Online UPS provides the highest level of protection by isolating the load from the raw mains.2.The "Static Bypass" switch allows the load to be transferred to the mains in case of inverter failure.3.Batteries in a UPS system should always be kept in a fully discharged state to improve life.Which of the statements given above is/are correct?

Correct Answer: C - 1 and 2 only

Quick Concept Explanation

An online double-conversion UPS isolates the critical load from many mains disturbances by continuously supplying it through the inverter. A static bypass transfers the load to an alternate mains path during inverter overload/failure or maintenance. Key relation: Online UPS path: AC→DC→DC link/battery→inverter→load.

Exam focus: Static bypass is an availability path, not energy storage. Common trap: Keeping batteries fully discharged does not improve life.

Statement-wise Verification

• Statement 1 - Correct.
  Online UPS provides the highest level of protection by isolating the load from the raw mains.
  An online double-conversion UPS isolates the critical load from many mains disturbances by continuously supplying it through the inverter.
• Statement 2 - Correct.
  The "Static Bypass" switch allows the load to be transferred to the mains in case of inverter failure.
  A static bypass transfers the load to an alternate mains path during inverter overload/failure or maintenance.
• Statement 3 - Incorrect.
  Batteries in a UPS system should always be kept in a fully discharged state to improve life.
  Deep discharge generally shortens battery life; UPS batteries are maintained charged according to their chemistry

Core Concept

An online double-conversion UPS isolates the critical load from many mains disturbances by continuously supplying it through the inverter. A static bypass transfers the load to an alternate mains path during inverter overload/failure or maintenance. Battery life is harmed by deep discharge and high temperature; batteries are maintained charged according to chemistry/manufacturer limits.

Formula / Key Relationship

Online UPS path: AC→DC→DC link/battery→inverter→load.

Why the Other Options Are Wrong

Option A is incorrect because it omits correct statement(s) 2. Option B is incorrect because it includes incorrect statement(s) 3 and omits correct statement(s) 1. Option D is incorrect because it includes incorrect statement(s) 3.

Exam Shortcut / Approach

Static bypass is an availability path, not energy storage.

Common Mistake

Keeping batteries fully discharged does not improve life.

Quick Revision

Online UPS Static Bypass and Battery Care is linked with UPS Systems, Power Backup and Industrial Automation. Static bypass is an availability path, not energy storage.