What are the elements of cost?

What are the elements of cost?

Elements of Cost

• Direct Material. It represents the raw material or goods necessary to produce or manufacture a product.
• Indirect Material. It refers to the material which we require to produce a product but is not directly identifiable.
• Direct Labour.
• Indirect Labour.
• Direct Expenses.
• Indirect Expenses.
• Overhead.
• Factory Overhead.

What is the difference between primary and secondary wires?

Primary wires are on top of the pole and usually carry 12,000 volts of electricity from a substation. The secondary wire carries the lower voltage electricity after it passes through the transformer. Telephone and cable wires are typically the lowest wires.

What is the difference between primary transmission and secondary transmission?

This stage is called as primary transmission. The voltage is the stepped down at a receiving station to 33kV or 66kV. Secondary transmission lines emerge from this receiving station to connect substations located near load centers (cities etc.). The voltage is stepped down again to 11kV at a substation.

What is secondary system?

The steam generator tubes, steam turbine, condenser, and associated pipes, pumps, and heaters used to convert the heat energy of the reactor coolant system into mechanical energy for electrical generation. Most commonly used in reference to pressurized water reactors.

What is a secondary power line?

Secondaries for residential service are three-wire single-phase circuits. They extend along the rear lot lines, alleys, or streets past customer’s premises. The secondaries can be overhead lines or underground lines. Overhead secondary lines are usually strung below the primary lines and typically in a vertical plane.

What is secondary voltage?

Secondary voltage is the coil winding supplying the output voltage. The output voltage of a transformer varies some with varying load resistances, even with a constant voltage input.

What is primary and secondary pump in HVAC?

The primary loop uses a constant speed pump to circulate the working fluid (water). The secondary loop uses a variable speed pump to manipulate the flow of the fluid such that the cooling coil demand is satisfied. The above mentioned pumps are considered as a primary/secondary pumping pair.

What is pump and types of pumps?

There are three basic types of pumps: positive-displacement, centrifugal and axial-flow pumps. In centrifugal pumps the direction of flow of the fluid changes by ninety degrees as it flows over impeller, while in axial flow pumps the direction of flow is unchanged.

What is a decoupler?

The decoupler allows excess primary water to flow back to the return side of the chillers, ensuring constant flow. The flow of chilled water in the primary loop of a P/S system is constant, while two-way valves and variable-speed-driven pumps in the secondary loop control coil capacity by varying water flow.

What is a header in HVAC?

secondary circuit in centralised hvac system. The primary and secondary circuits are connected via a pipe known as the “Low Loss Header” it is also sometimes referred to as the “Decoupler” or “Common Header”. The primary water flows into this to provide heated or chilled water to the secondary circuits.

When should I use a low loss header?

A low loss header is typically used as ‘hydraulic separation’ between any two or more circulating pumps within a heating system. This hydraulic separation allows each pump to work independently at their own flowrates without pulling or pushing on the other.

What is inside a low loss header?

A low loss header usually has a drain at the bottom of it. Hot water passes through the header at a lower pressure than it would pass through the rest of the system. This reduction in pressure and speed allows time for any dirt and debris in the system to sink to the bottom of the header.

What is chilled water pump?

Chilled water pumps circulate the water through the pipes and heat exchanger. The units are generally large end suction or Horizontal split casing pumps running at 1450 rpm. The pumps are coupled with motors and supplied as one unit.

How does a chilled water pump work?

The chilled water pump circulates return chilled water from the air handling units & fan coil units back to the chiller. The chiller then cools the chilled water and the chilled water is then supplied back to the air handling units and fan coil units. The chilled water pump circulates chilled water through the system.

How many types of chillers are there?

three different types

What is process chilled water?

Process Chilled Water Systems (PCW) are compact, skid mounted systems that circulate process water at a consistent temperature and pressure to the application’s point of use and back, allowing for more efficient and stable use of water-cooled machines, equipment and instruments.