Cable & Wireless Worldwide Interview Questions and Answers

In primary pump systems without a bypass valve, we can use a variable frequency drive (VFD) to control the pump speed.

• Use a variable frequency drive (VFD) to adjust the speed of the pump based on system demand

• VFDs can help maintain system pressure and flow without the need for a bypass valve

• VFDs can also improve energy efficiency by matching pump speed to actual system requirements

The types of AHU modes include cooling mode, heating mode, and ventilation mode.

• Cooling mode: AHU cools the air before circulating it throughout the building.

• Heating mode: AHU heats the air before circulating it throughout the building.

• Ventilation mode: AHU circulates fresh air throughout the building without heating or cooling.

I have experience working with various building automation systems, including but not limited to Siemens, Honeywell, and Johnson Controls.

• Experience with Siemens building automation systems

• Experience with Honeywell building automation systems

• Experience with Johnson Controls building automation systems

Heatwheel and Energy wheel are both types of energy recovery ventilation systems used in HVAC systems, but they differ in their specific mechanisms and applications.

• Heatwheel uses a rotating wheel with a desiccant coating to transfer heat and moisture between incoming and outgoing air streams, while Energy wheel uses a rotating wheel with a matrix of heat-absorbing material to transfer heat only.

• Heatwheel is more effective in transferring both heat and moisture, making it sui...read more

Safety system architecture refers to the design and structure of systems that ensure the safety of operations and prevent accidents.

• Safety system architecture involves the arrangement of components, functions, and interfaces to achieve safety goals.

• It includes redundancy, fault tolerance, and fail-safe mechanisms to minimize the risk of failures.

• Examples include safety-critical systems in industries such as aerospace, automotive, and nuclear power plants.