ResourcesSingle-line diagram symbolsSubstation single-line diagram
Double busbar
A 10 kV switchboard with two busbars, each split into section I and section II by a section breaker. Two incomers, a bus coupler between the busbars, every bay on both busbars through two disconnectors, and four outgoing bays.
Free to use and modify in your own projects, including commercial ones. The ZIP holds the sample drawing, a template, a plot style table and a README; no add-in needed. The data in the drawing is made up, so it is not for design or construction. Provided as is, without warranty. Library terms (CXL-1.0)
Version 1.0 · updated October 20, 2026
This sample uses these resources
The symbols are blocks from our own libraries, with their attributes filled in. The sheet and its title block come from our ISO A3 title block template. Download them to draw your own diagrams.
Layers, styles and sheet setup are the same for every drawing in the series; they are described on the series page: Substation single-line diagram
Title block fields
The attributes of the title block. Double-click it to fill them in, or write them for a whole set of drawings with BlockSync.
| Attribute | Field on the sheet | Value in this sample |
|---|---|---|
| COMPANY | COMPANY | CADXChange |
| PROJECT | PROJECT | 10/0.4 kV Distribution Substation |
| AREA | AREA | Substation |
| SYSTEM | SYSTEM | 10 kV |
| CLIENT | CLIENT | Sample |
| TITLE | DRAWING TITLE | Single-line diagram, double busbar |
| DRAWING_NO | DRAWING NO. | E-002 |
| CONTRACT_NO | CONTRACT NO. | — |
| REV | REV | A |
| DRAWN | DRAWN | — |
| CHECKED | CHECKED | — |
| APPROVED | APPROVED | — |
| DATE | DATE | 2026-10-20 |
| SCALE | SCALE | NTS |
| SHEET | SHEET | 1 |
| SHEET_OF | OF | 1 |
Revision table: R1 to R4, each with REV, DATE, DESCRIPTION and BY (16 attributes, empty in this sample).
Blocks in the drawing
The equipment list of the drawing: block name, symbol and how many times it is placed. BlockSync exports the same list from your own drawings.
| Symbol | Block | Placed |
|---|---|---|
 Disconnector | PWR_DISCONNECTOR | 14 |
 Circuit breaker, vacuum | PWR_CB_VCB | 9 |
 Current transformer | PWR_CT | 6 |
 Grid infeed (utility source) | PWR_GRID | 2 |
 Relay, overcurrent (50/51) | PWR_R_5051 | 2 |
 Transformer, delta-star, neutral earthed | PWR_TX_DYN | 2 |
 Fuse | PWR_FUSE | 1 |
 Voltage transformer | PWR_VT | 1 |
 Earth | PWR_EARTH | 1 |
 Motor, induction | PWR_MOTOR_IM | 1 |
 Load (static) | PWR_LOAD | 1 |
Equipment schedule
One row per placed symbol, read from the attributes of the blocks in the drawing: what is shown on the sheet, and the schedule attributes that were filled in but are not shown. BlockSync exports these same attributes from your own drawings.
| Tag | Description | Shown on the sheet | Filled in, not shown |
|---|---|---|---|
| QF4 | Circuit breaker, vacuumPWR_CB_VCB | RATED_KV = 12 kV | RATED_CURRENT_A = 630BREAKING_KA = 25INTERRUPTER = VacuumMECHANISM = SpringCONTROL_VOLTAGE = 110 V DC |
| QF5 | Circuit breaker, vacuumPWR_CB_VCB | RATED_KV = 12 kV | RATED_CURRENT_A = 630BREAKING_KA = 25INTERRUPTER = VacuumMECHANISM = SpringCONTROL_VOLTAGE = 110 V DC |
| G1 | Grid infeed (utility source)PWR_GRID | RATING = 250 MVA | VOLTAGE_KV = 10 |
| QF1 | Circuit breaker, vacuumPWR_CB_VCB | RATED_KV = 12 kV | RATED_CURRENT_A = 630BREAKING_KA = 25INTERRUPTER = VacuumMECHANISM = SpringCONTROL_VOLTAGE = 110 V DC |
| TA1 | Current transformerPWR_CT | RATIO = 400/1 A | CLASS = 5P20BURDEN_VA = 15CORES = 2RATED_KV = 12 |
| QS11 | DisconnectorPWR_DISCONNECTOR | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual | |
| QS12 | DisconnectorPWR_DISCONNECTOR | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual | |
| F1 | Relay, overcurrent (50/51)PWR_R_5051 | FUNCTION = OC / EF | SETTING = I> 1.2 In, 0.3 s; I>> 8 In, 0.1 sTRIPS = QF1CT_INPUT = TA1 |
| G2 | Grid infeed (utility source)PWR_GRID | RATING = 250 MVA | VOLTAGE_KV = 10 |
| QF2 | Circuit breaker, vacuumPWR_CB_VCB | RATED_KV = 12 kV | RATED_CURRENT_A = 630BREAKING_KA = 25INTERRUPTER = VacuumMECHANISM = SpringCONTROL_VOLTAGE = 110 V DC |
| TA2 | Current transformerPWR_CT | RATIO = 400/1 A | CLASS = 5P20BURDEN_VA = 15CORES = 2RATED_KV = 12 |
| QS21 | DisconnectorPWR_DISCONNECTOR | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual | |
| QS22 | DisconnectorPWR_DISCONNECTOR | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual | |
| F2 | Relay, overcurrent (50/51)PWR_R_5051 | FUNCTION = OC / EF | SETTING = I> 1.2 In, 0.3 s; I>> 8 In, 0.1 sTRIPS = QF2CT_INPUT = TA2 |
| QS31 | DisconnectorPWR_DISCONNECTOR | RATED_KV = 12 kV | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual |
| QF3 | Circuit breaker, vacuumPWR_CB_VCB | RATED_KV = 12 kV | RATED_CURRENT_A = 630BREAKING_KA = 25INTERRUPTER = VacuumMECHANISM = SpringCONTROL_VOLTAGE = 110 V DC |
| QS32 | DisconnectorPWR_DISCONNECTOR | RATED_KV = 12 kV | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual |
| FU1 | FusePWR_FUSE | RATED_KV = 12 kV | RATED_CURRENT_A = 6BREAKING_KA = 50CHARACTERISTIC = Current limiting |
| TV1 | Voltage transformerPWR_VT | RATIO = 10/0.1 kV | CLASS = 0.5BURDEN_VA = 50WINDINGS = 2RATED_KV = 12 |
| E1 | EarthPWR_EARTH | EARTH_TYPE = PE | |
| QS101 | DisconnectorPWR_DISCONNECTOR | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual | |
| QS102 | DisconnectorPWR_DISCONNECTOR | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual | |
| QF10 | Circuit breaker, vacuumPWR_CB_VCB | RATED_KV = 12 kV | RATED_CURRENT_A = 630BREAKING_KA = 25INTERRUPTER = VacuumMECHANISM = SpringCONTROL_VOLTAGE = 110 V DC |
| TA10 | Current transformerPWR_CT | RATIO = 200/1 A | CLASS = 5P20BURDEN_VA = 15CORES = 2RATED_KV = 12 |
| T1 | Transformer, delta-star, neutral earthedPWR_TX_DYN | RATING_MVA = 1.6 MVA | VOLTAGE_RATIO = 10/0.4 kVVECTOR_GROUP = Dyn11IMPEDANCE_PCT = 6TAP_RANGE = +/-2x2.5%COOLING = ONANNEUTRAL_EARTHING = Solid |
| QS111 | DisconnectorPWR_DISCONNECTOR | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual | |
| QS112 | DisconnectorPWR_DISCONNECTOR | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual | |
| QF11 | Circuit breaker, vacuumPWR_CB_VCB | RATED_KV = 12 kV | RATED_CURRENT_A = 630BREAKING_KA = 25INTERRUPTER = VacuumMECHANISM = SpringCONTROL_VOLTAGE = 110 V DC |
| TA11 | Current transformerPWR_CT | RATIO = 200/1 A | CLASS = 5P20BURDEN_VA = 15CORES = 2RATED_KV = 12 |
| T2 | Transformer, delta-star, neutral earthedPWR_TX_DYN | RATING_MVA = 1.6 MVA | VOLTAGE_RATIO = 10/0.4 kVVECTOR_GROUP = Dyn11IMPEDANCE_PCT = 6TAP_RANGE = +/-2x2.5%COOLING = ONANNEUTRAL_EARTHING = Solid |
| QS121 | DisconnectorPWR_DISCONNECTOR | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual | |
| QS122 | DisconnectorPWR_DISCONNECTOR | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual | |
| QF12 | Circuit breaker, vacuumPWR_CB_VCB | RATED_KV = 12 kV | RATED_CURRENT_A = 630BREAKING_KA = 25INTERRUPTER = VacuumMECHANISM = SpringCONTROL_VOLTAGE = 110 V DC |
| TA12 | Current transformerPWR_CT | RATIO = 200/1 A | CLASS = 5P20BURDEN_VA = 15CORES = 2RATED_KV = 12 |
| M1 | Motor, inductionPWR_MOTOR_IM | POWER_KW = 800 kW | VOLTAGE = 10 kVPOWER_FACTOR = 0.85STARTING = Star-deltaSERVICE = Compressor K-101 |
| QS131 | DisconnectorPWR_DISCONNECTOR | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual | |
| QS132 | DisconnectorPWR_DISCONNECTOR | RATED_CURRENT_A = 630SHORT_TIME_KA = 25EARTHING_SWITCH = NoMECHANISM = Manual | |
| QF13 | Circuit breaker, vacuumPWR_CB_VCB | RATED_KV = 12 kV | RATED_CURRENT_A = 630BREAKING_KA = 25INTERRUPTER = VacuumMECHANISM = SpringCONTROL_VOLTAGE = 110 V DC |
| TA13 | Current transformerPWR_CT | RATIO = 200/1 A | CLASS = 5P20BURDEN_VA = 15CORES = 2RATED_KV = 12 |
| L1 | Load (static)PWR_LOAD | POWER_KW = 2500 kW | VOLTAGE = 10 kVPOWER_FACTOR = 0.95SERVICE = To substation SS-2 |
Manufacturer, model and remarks are left empty on every block, ready for your data. The values are examples.
