Create a free account to save this calculation, add it to a project or export a report.

Load Schedule Calculator

BS 7671:2018+A4:2026

Total L1 — Diversified

226.78A

Phase 1 demand

Total L2 — Diversified

175.10A

Phase 2 demand

Total L3 — Diversified

175.10A

Phase 3 demand

Phase Imbalance

17.9%

Acceptable

(max − avg) / avg · guidance only

Main DistributionL1: 226.78 AL2: 175.10 AL3: 175.10 A

Board Name	Type	Description	Location	Voltage	Conn. L1	Conn. L2	Conn. L3	Item-Div. L1	Item-Div. L2	Item-Div. L3	DF	Div. L1	Div. L2	Div. L3	Device	Rating (A)
					285.00	237.00	237.00	202.30	175.10	175.10		202.30	175.10	175.10
					48.00	0.00	0.00	27.20	0.00	0.00		24.48	0.00	0.00

Mechanical SuppliesL1: 155.10 AL2: 155.10 AL3: 155.10 A

Name	Type	Description	Location	Origin	Voltage	L1 (A)	L2 (A)	L3 (A)	DF	Div. L1	Div. L2	Div. L3	Device	Rating (A)
										129.50	129.50	129.50
										25.60	25.60	25.60

Small PowerL1: 25.60 AL2: 0.00 AL3: 0.00 A

Name	Type	Description	Location	Origin	Voltage	L1 (A)	L2 (A)	L3 (A)	DF	Div. L1	Div. L2	Div. L3	Device	Rating (A)
										12.80	0.00	0.00
										12.80	0.00	0.00

LightingL1: 28.80 AL2: 0.00 AL3: 0.00 A

Name	Type	Description	Location	Origin	Voltage	L1 (A)	L2 (A)	L3 (A)	DF	Div. L1	Div. L2	Div. L3	Device	Rating (A)
										14.40	0.00	0.00
										14.40	0.00	0.00

Specialist SuppliesL1: 20.00 AL2: 20.00 AL3: 20.00 A

Name	Type	Description	Location	Origin	Voltage	L1 (A)	L2 (A)	L3 (A)	DF	Div. L1	Div. L2	Div. L3	Device	Rating (A)
										20.00	20.00	20.00

Questions

›What does the DF column do?

DF is a diversity factor applied to connected current. On a load item it reduces that item, for example a 185 A chiller at a DF of 0.7 contributes 129.50 A. On a distribution board it is applied to the board’s total after each item’s own factor. Leave it blank to take the full connected load.

›How is phase imbalance calculated?

As the difference between the most heavily loaded phase and the average of the three, divided by the average. With diversified phase totals of 226.78 A, 175.10 A and 175.10 A, the average is 192.33 A and the imbalance is 17.9%. The calculator shows this as guidance; it is not a BS 7671 pass or fail.

›Does the load schedule size cables?

No. It totals connected and diversified load per phase across boards, mechanical supplies and small power. Use the totals in the Volt Drop calculator, or in Circuit and Infrastructure on Professional, to size the cables that feed them.