Why Shorting Frames Matter in EW Plants?

Precision Technology

In copper electrowinning operations, the shorting circuit frame—also referred to as a cell isolator —is an essential yet often overlooked component. Together with its companion storage rack, it plays a critical role in ensuring safe current distribution, minimizing energy loss, and protecting equipment during maintenance or emergency shutdowns.

At PRS, we engineer these systems to withstand extreme currents, corrosive environments, and mechanical stress. This article breaks down their design, materials, and the advanced testing protocols that guarantee reliability.

1. How Do Shorting Circuit Frames and Storage Racks Work?

Shorting Circuit Frame

Function: Safely redirects current from electrolytic cells during maintenance, preventing damage to rectifiers and transformers.
Applications: Essential for cell cleaning, cathode replacement, and emergency shutdowns.

Storage Rack

Function: When the shorting circuit frame is idle and not in use, it is used for placing and securing the shorting circuit frame.
Key Feature: Adjustable leveling bolts at the base accommodate uneven floors in harsh environments.

2. Structural Design & Material Selection

Shorting Circuit Frame Components

Lifting Frame
- Material: S.S.316L stainless steel.
- Why SS316L?: Superior corrosion resistance in acidic/chloride-rich environments (common in electrowinning plants).
Conductive Copper Bus Bars
- Material: LME Grade A copper (ASTM C11000).
- Specs: Conductivity ≥100% IACS, ensuring minimal voltage drop.
Cooling Water Pipes
- Material: S.S.316L
- Function: Circulate coolant to dissipate heat from high-current operations.

Storage Rack Design

Modular Structure: Bolt-on assembly for easy installation and disassemblyand the bottom of the storage rack is designed with leveling bolts.
Material: S.S.316L.

3. Surface Treatment: Tin-Plated Copper Bus Bars

PRS applies electrolytic tin plating to copper bus bars, offering:

Oxidation Resistance: Extends lifespan in humid or acidic conditions.
Low Contact Resistance: Maintains stable conductivity even after repeated use.
Cost Efficiency: 30% cheaper than silver plating with 95% performance retention.

Comparison:

Parameter	Bare Copper	Tin-Plated	Silver-Plated
Corrosion Resistance	Poor	Excellent	Good
Cost	$	$$	$$$$
Conductivity	100% IACS	98% IACS	105% IACS

4. PRS’s Technical Services: Simulation Testing for Peak Performance

Before delivery, every PRS shorting circuit frame undergoes rigorous simulations by software:

Maximum Current Test
- Validates the frame’s capacity to handle peak currents (e.g., 100kA for 1 hour) without deformation.
- Deliverable: A simulation testreport with current-time curves and safety margins.

The Current(max.) Pass Through the Copper Bar
Section	Area(mm²)	Imax(A)	CD(A/mm²)	Remark
1	5400	5500	1.02	Current from 7.5 electrodes
2	5400	5500	1.02	Current from 7.5 electrodes
3	10800	11000	1.02	Current from 15 electrodes
4	10800	11000	1.02	Current from 15 electrodes
5	16200	16500	1.02	Current from 22.5 electrodes
6	16200	16500	1.02	Current from 22.5 electrodes
7	21600	22000	1.02	Current from 30 electrodes
8	21600	22000	1.02	Current from 30 electrodes
9	8200	5867	0.72	Current from 8 electrodes

Temperature Rise Simulation
- Predicts thermal behavior using CFD modeling, ensuring temperature rise stays <40°C under full load.
- Deliverable: Thermal distribution maps and cooling recommendations.

Static Stress Analysis
- Evaluate the overall structural load capacity of the shorting circuit frame when lifted by slings.
- Deliverable: Static stress simulation test report.

Conclusion

A well-designed shorting circuit frame and storage rack system is not just a safety net—it’s a strategic investment. By combining corrosion-resistant materials, precision engineering, and predictive testing, PRS ensures your plant operates safely, efficiently, and profitably.