With reference to storage batteries, explain EACH of the following: (a) the term UPS;(3) (b) the operation of an inverter, stating why it may be required;(4) (c) the term 150 Ah.(3)
(a) The term UPS (3 marks)
UPS stands for Uninterruptible Power Supply.
It is a system that provides an instantaneous supply of electrical power from storage batteries if the main supply fails.
It ensures that critical systems (navigation, communications, alarms, control circuits) continue operating without interruption during power loss or changeover.
(b) Operation of an inverter, stating why it may be required (4 marks)
An inverter is an electronic device that converts direct current (DC) from storage batteries into alternating current (AC).
It uses semiconductor switches (e.g., transistors or thyristors) to chop DC into pulses, then smooths and shapes the output into AC of the required frequency (e.g., 50/60 Hz).
It may be required because many shipboard systems, computers, and electronic controls are designed to operate on AC power, while batteries only supply DC.
Thus, the inverter enables battery-stored energy to supply AC-only equipment during blackouts or UPS operation.
(c) The term 150 Ah (3 marks)
150 Ah means the battery has a capacity of 150 ampere-hours.
This is a measure of the total charge the battery can deliver: it can theoretically supply 150 amps for 1 hour, or 15 amps for 10 hours, before being fully discharged.
It defines the energy storage capacity and is used for sizing batteries to ensure sufficient standby duration for essential services.
