Lecture 13 Electrical System Estimate Residential

Shop Practice with Electrical Code: Electrical Estimate (Residential) Jayson Bryan E. Mutuc, REE, RME BSEE-PUP MSEE, Major in Power Systems -MIT (candidate)

Direct Estimate Estimation of Materials Wires Conduits, Elbows Junction and Utility Box Locknut and Bushing Switches Convenience Outlet Circuit Breakers Panel Board Miscellaneous

Service Cap Adapter(PVC) Lighting Fixture

Estimate table format Approved Budget for the Contract Project Title: Project Location: Item No.

Item Description

Qty

Unit

Direct Cost

Estimated Direct Cost

Material Cost

Labor Cost

Unit Cost

Unit Cost

Total Cost

Total Cost

Computation for Estimate Labor Cost – 30% of Material Cost

Qty of Conduits – total computed length / 3

Total length of Wires – total length of wire x 2 (ungrounded) total length of wire x 3 (grounded) “color of ground wire is green/white”

Qty of utility boxes - total number of switches and convenience outlet visible to the plan

Qty of junction boxes – total number of lighting outlet and junction box visible to the plan

Qty of Circuit Breaker – total number of circuits in the electrical plan plus the spares

Qty. of Locknut and bushing – 1 per utility box(in switch) 2 or 1(in convenience), no. of circuits in panelboard plus runway to service entrance, service cap and grounding conductor

Qty of Adapter – equal to the number of locknut and bushing

No. of Conduit Elbow – depends on the number 90° bends visible to the plan

Or sometimes the contractor doesn’t use conduit instead they use blue torch to the conduit to make a 90° bend

Qty of switches – total number of lighting switches visible to the plan

Qty of convenience outlet – total number of convenience outlet visible to the plan including acu’s, range, water heater, etc.

Coupling – used to connect conduit to conduit when there’s a shortage in conduit length

Lighting Fixtures

Size of Panel Board – depends on the number of branch circuits plus main breaker

Service Cap – one service cap for single dwelling

Miscellaneous: Electrical Tape and Rubber Tape – uses to insulate the joints and splices

G.I. wires – use to tie up the rough-in of switches, convenience outlet, etc.

Parts of Estimate Electrical Works 1. Roughing-Ins (conduit, adapter, locknut and bushing) 2. Wires and Cables 3. Wiring Devices (outlets, switches, utility, and junction box) 4. Lighting Fixtures 5. Panelboards 6. Miscellaneous

Quantity Units Meters – used for the length wires Rolls – 1 box of wire most of 1roll = 150meters Pieces – used for the quantities conduits, adapter, elbows, locknut, bushing, electrical tape, rubber tape, Kg – used for G.I. wires Lot – package quantity example 1lot = 1000piece Assy – assembly usually used in panelboards