LB RL
Resistive-reactive load bank
A test load bank combining resistive and inductive steps to load a generator at its rated power factor.
SLD
Symbols · LB
Resistive load bank
A bank of switched resistive elements used to apply a controllable test load to generators, UPS or battery systems.
In plain English
What does Resistive load bank mean?
A resistive load bank is a set of resistor elements, switched in steps and cooled by fans, used to load a generator, UPS or battery system for commissioning and maintenance tests. Permanent load banks are also installed to keep diesel engines above minimum load when site demand is low.
A simple example
Drawings show a resistor symbol or a group of resistors with step switches, connected through a breaker to the bus being tested. Permanently installed banks have a control link to the genset or microgrid controller, while portable banks connect through a temporary test connection point.
What the drawings help you do
A resistive bank loads at unity power factor only, so it does not test a generator at its rated kVA when the rated power factor is below one. The symbol does not show step sizes or fan supply, both needed for test planning.
This particular reference
A bank of switched resistive elements used to apply a controllable test load to generators, UPS or battery systems. A resistive load bank applies only active load; a resistive-reactive bank can also apply lagging kvar.
- Terminal
- An identified point where a conductor connects.
- Rating
- A value stating the conditions for which equipment is specified.
- Schematic
- A drawing showing function and connections rather than physical appearance.
Read the source: T-030 liquid-cooled generator set application manual · Resistors and heater-element symbols
SLD · LB
What it represents
A resistive load bank is a set of resistor elements, switched in steps and cooled by fans, used to load a generator, UPS or battery system for commissioning and maintenance tests. Permanent load banks are also installed to keep diesel engines above minimum load when site demand is low.
Drawings show a resistor symbol or a group of resistors with step switches, connected through a breaker to the bus being tested. Permanently installed banks have a control link to the genset or microgrid controller, while portable banks connect through a temporary test connection point.
A resistive bank loads at unity power factor only, so it does not test a generator at its rated kVA when the rated power factor is below one. The symbol does not show step sizes or fan supply, both needed for test planning.
How to read it
- A purely resistive bank tests kW, not kVA.
- Look for a dedicated test connection point.
Information to show or reference
- State kW rating and step sizes.
- Show breaker and fan supply.
- Reference control interface.
A distinction that matters
A resistive load bank applies only active load; a resistive-reactive bank can also apply lagging kvar.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
T-030 liquid-cooled generator set application manual
Public generator application manual context for testing and minimum load.
Resistors and heater-element symbols
Public resistor symbol family context.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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