By HuaQuan Engineering TeamPublished: 2026-07-17Category: Wiki Encyclopedia
Definition
Load shedding is the deliberate disconnection of non-critical loads during generator operation to: (1) prevent overload and shutdown, (2) manage limited generator capacity, (3) prioritize critical loads (life safety, data centers). Controlled by: PLC or generator controller with programmable priority levels. Common in grid-constrained regions where generator supply is limited. Normal loads restored when capacity allows.
What is Load Shedding — Generator Load Management Strategy
Overview
Load shedding is the deliberate disconnection of non-critical loads during generator operation to: (1) prevent overload and shutdown, (2) manage limited generator capacity, (3) prioritize critical loads (life safety, data centers). Controlled by: PLC or generator controller with programmable priority levels. Common in grid-constrained regions where generator supply is limited. Normal loads restored when capacity allows.
How It Works
This configuration addresses specific power generation requirements through specialized equipment selection and control strategies.
Key Considerations
Proper implementation requires careful planning, correct equipment sizing, and compliance with local codes and standards.
| Parameter | Specification | Notes |
|---|
| Application | Per description | Application-specific |
| Power range | Varies | Depends on configuration |
| Fuel type | Per design | Application optimized |
| Control system | Advanced | Integrated PLC/controller |
| Advantage | Benefit | Typical Impact |
|---|
| Efficiency | Optimized operation | 15-40% improvement |
| Reliability | Designed for purpose | High availability |
| Cost | Total lifecycle | ROI dependent on application |
| Environment | Reduced emissions | Per local regulations |
| Industry | Application | Typical Size | Key Requirement |
|---|
| Mining | Remote power | 1-20 MW | Reliability, altitude |
| Oil & Gas | Field power | 500 kW-10 MW | ATEX/IECEx hazardous area |
| Data Center | Backup + prime | 1-10 MW | Tier certification |
| Hospital | Life safety backup | 500-2000 kW | NFPA 110 Level 1 |
Key Takeaways
- Understanding Load Shedding — Generator Load Management Strategy helps in selecting the right power solution.
- Application-specific considerations significantly impact generator selection and design.
- Modern control systems enable integration of multiple power sources for optimal performance.
- Compliance with applicable standards and regulations is mandatory for safe and legal operation.
Quick Reference
- Definition: See definition card
- Relevant standard: ISO 8528, NFPA 110, IEC 60034
- Related: Generator Sizing, Installation, Maintenance
Frequently Asked Questions
What is synchronizing?
Synchronization matches voltage, frequency, phase angle, and phase sequence before connecting a generator to a live bus. Auto-synchronizers control speed and voltage automatically.
What is NFPA 110?
NFPA 110 is the US standard for emergency and standby power systems. Level 1: life safety (hospitals, high-rise). Level 2: less critical. Defines transfer time, testing, and maintenance.
What is ISO 8528?
ISO 8528 is the international standard for reciprocating internal combustion engine driven AC generating sets. Defines ratings, performance, testing, and documentation requirements.
What is a transfer switch (ATS)?
An ATS automatically switches load between utility and generator. Types: open transition, closed transition (make-before-break), soft-loading. NFPA 110 requires <10 sec transfer.
What is AVR in a generator?
AVR (Automatic Voltage Regulator) maintains generator output voltage within ±1% by controlling exciter field current. Modern digital AVRs offer soft start, voltage matching, and Modbus communication.
What is a turbocharger?
A turbocharger uses exhaust gas energy to compress intake air, increasing engine power density 30-50%. Critical for modern high-output diesel engines.
What is biodiesel?
Biodiesel is renewable fuel from vegetable oils or animal fats. B20 compatible with most diesel engines. B100 requires engine modifications.
What is a load bank test?
Load bank testing applies artificial load (75-100%) to exercise generator. Prevents wet stacking, verifies capacity, tests cooling system. Recommended monthly for standby units.
What is common rail injection?
Common rail maintains constant high fuel pressure (up to 2500 bar) with electronically controlled injectors. Benefits: precise timing, better atomization, lower emissions, 5-8% fuel savings.
What is generator derating?
Derating reduces output for environmental conditions. Altitude: -1% per 100m above 1000m. Temperature: -1% per 10°C above 25°C.
What is a standby generator rating?
Standby rating: maximum power for emergency use, 200-250 hours/year max, no overload. Typical for backup applications. Also called Emergency Standby Power (ESP).
What is the difference between kW and kVA?
kW (kilowatt) = real power consumed. kVA = apparent power. kW = kVA x Power Factor. Standard PF is 0.8: 100 kVA = 80 kW.
What is wet stacking?
Wet stacking occurs when diesel engines run at <30% load for extended periods, causing unburned fuel accumulation. Prevention: load bank testing at 75%+ load monthly.
What is IP rating?
IP (Ingress Protection) indicates enclosure protection. IP44: spray water. IP54: dust protected. IP65: dust tight + water jets. Generator enclosures typically IP44-IP65.
What is genset paralleling?
Paralleling connects multiple generators to a common bus to increase capacity, improve reliability (N+1), and enable maintenance without shutdown. Requires synchronization and load sharing.