Transformer Vacuum Packages
The SES420 family of vacuum packages are targeted at transformer dry out applications but can be custom engineered for other industrial applications on request. The SES420 series is packaged in four standard size ranges (375, 700, 1200, and 1650 CFM) with backing vacuum pump type, booster bypass, and VFD atmospheric startup options. These systems are available as stand-alone skids, stand-alone cargo trailer packages, and SES320 oil processor integrated systems.
SES420 Highlights
- Two Stage Vacuum Systems
- Direct Drive Booster Pumps
- 375, 700, 1200, and 1650 CFM Standard Flow Ranges
- Dry Screw, Two Stage Piston, and Rotary Vane Backing Pump Options
- VFD Atmospheric Booster Start and Internal Bypass Booster Options
Designed primarily for transformer dry out applications, the SES420 family provides flexible vacuum system configurations with multiple backing pump, vacuum booster, and mounting options. Packages are available from 375 to 1650 CFM and can be supplied as stand-alone systems or integrated into transformer oil processing equipment.
Vacuum Pumps
Oil Sealed Rotary Vane
SES420-1650 / SES420-1200 / SES420-700 / SES420-375
Vane pumps are the least expensive option and require the most maintenance time and cost. Single-stage vane pump supported packages have a slightly higher ultimate vacuum pressure than screw and piston pump supported packages.
Single Stage Oil Sealed Rotary Piston
SES420-1650 / SES420-1200 / SES420-700 / SES420-375
Piston pumps are time proven, more robust than vane pumps, and less expensive to repair than screw pumps. Air cooled pumps are available in smaller package sizes, while larger systems utilize liquid cooled pumps with closed loop cooling.
Two Stage Oil Sealed Rotary Piston
SES420-1650 / SES420-1200 / SES420-700 / SES420-375
Two-stage piston pump designs eliminate many performance issues associated with contaminated seal oil, providing more consistent operation when processing heavily moisture-laden transformer systems.
Dry Compression Rotary Screw
SES420-1650 / SES420-1200 / SES420-700 / SES420-375
Dry screw pump supported systems provide the lowest ultimate vacuum pressures and highest throughputs while eliminating seal oil maintenance. Maintenance time and operating cost are significantly reduced compared to vane and piston technologies.
Booster Pumps
Standard Non-Bypass Vacuum Booster
SES420-1650 / SES420-1200 / SES420-700 / SES420-375
Standard packages utilize an Aerzen direct drive Roots-style rotary lobe booster without an internal bypass valve. Pressure cut-in switches activate the booster at approximately 10-15 Torr depending on package size and backing pump selection.
Optional VFD Controlled Vacuum Booster
SES420-1650 / SES420-1200 / SES420-700 / SES420-375
VFD control allows atmospheric startup and eliminates the need for a pressure cut-in switch. The booster operates at reduced speed throughout the pump down cycle, reducing transformer evacuation times by approximately 20%.
Optional Bypass Vacuum Booster
SES420-1200 / SES420-700
Optional Leybold direct drive Roots-style rotary lobe booster with internal bypass valve. The bypass valve closes at 35 Torr and utilizes coordinated cut-in control.
Features & Options
SES420 Standard Features
- Safety booster pump discharge high temperature shutdown interlock
- Panel mounted digital full scale vacuum gauge
- NEMA 4 control panel with PLC logic
- No fuses, 100% circuit breaker protected
Available System Options
- Safety oil trap with high level shutdown interlock
- Panel mounted remote vacuum gauge with 200' cable
- Automatic vacuum shut-off valve with pneumatic spring return actuator
- Vacuum line dew point monitor
- Vacuum line cold trap
Mounting
The SES420 can be stand-alone skid-mounted, packaged in an easy-to-tow cargo trailer, or integrated into a SES320 Conditioning System or a SES441 Filtration System.
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Skid Mounting
Built-to-order skid-mounted equipment can normally be built to meet customer footprint and access requirements. Consult SESCO with special requests.
Cargo Trailer Mounting
All cargo trailers are specifically engineered to accommodate equipment load, weight distribution, to provide optimum towing conditions. Cargo trailer weight capacities (GVRW) range from 4,000 to 16,000 Lbs. SESCO will provide the cargo trailer size and weight capacity options available for the system being quoted.
