Typical Specifications
Rotary Puffer, Overhead Switchgear
Two Position

This specification covers the requirements for manual load break SF6 rotary puffer (RP) style switches for overhead applications.

A. SWITCH CONSTRUCTION
Switch contacts and cable entrance terminations shall be contained in a single welded, mild steel tank with entrances internally connected by tin plated copper. The protection degree of the switch tank shall be IPX7 rated. Switches shall be shipped filled with SF6 gas at approx. 9 psig (60kPa).

B. DESIGN RATINGS AND STANDARDS
Switches shall be designed, tested, and built per applicable sections of ANSI and IEC standards. Certified test reports shall be provided. The manufacturer shall be ISO 9001:2000 and 14001 certified. The switch assembly shall be rated:

C. SWITCH CONTACTS
Switch contacts shall be of a rotary puffer design made with copper alloy contacts with silver plating to assure permanent, low contact resistance. Each rotating contact simultaneously disengages from two fixed contacts, thus providing two break points per phase which gives improved interrupting capability as compared to switches with only a single set of break contacts. Contact travel shall be 90° to assure efficient arc extinction and a wide open contact gap. Arcing is confined away from the main contact surfaces. The stationary contacts shall be supported independent of the cable entrance bushings, eliminating possible misalignment. Temperature rise shall not exceed ANSI C37.71 and IEC 265-1 standards for this type of device.

D. SWITCH OPERATION
Each switch shall be equipped with spring assisted operating mechanism capable of providing quick-make, quick-break operation. The mechanism shall be capable of delivering sufficient torque and shall be provided with latches for each position to achieve the published load interrupting, fault closing, and momentary ratings. All switch positions shall be clearly identified and padlockable. The operating mechanism shall be actuated from outside the switch tank by a permanently attached operating handle or motor actuator. The operating shaft shall be made of brass for maximum corrosion resistance. A double “O” ring type operating shaft seal shall be used for a leak resistant, long life seal. Ambient temperature range shall be -30°C to +40°C (-22°F to +104°F).

E. STANDARD COMPONENTS
For a manual switch the following shall be included:

- Eleven gauge mild steel tank painted light gray with stainless steel and brass fasteners

- Two lifting eyes

- Crossarm or pole mounting bracket and hardware

- Grounding provisions

- Gas pressure gauge and fill valve

- Three line diagram and corrosion resistant nameplate

- Spring operator

- Manual operating handle

- Colored contact position indicator (open/green, closed/red)

- Padlock provisions for open and close positions

- Porcelain bushings with copper conductor and hoodnut

- Lightning arrester provisions

- Operations counter

F. MOUNTING
Switches shall be equipped with:

- Crossarm mounting kit

- Polemount bracket (horizontal)

- Polemount bracket (vertical)

G. OPTIONAL COMPONENTS (check)
The following options shall be supplied:

___ Stainless steel tank

___ Low pressure warning device

___ 4/0 brass ground lug

___ NEMA 2-hole aerial lugs

___ NEMA 4-hole aerial lugs

___ Clamp style aerial lugs

___ Overpressure relief device

___ Wild life protectors

___ Surge arresters

___ Potential transformers

___ Current transformers (600:5) (500:1) (1000:1)

___ Automatic transfer control for 6-8 second transfer

___ Down rod operator kit, does not include rods

___ Motor actuator

___ Analog voltage sensors

___ 600A porcelain bushings with copper rod

___ 600A apparatus bushing with elastomeric insulator and (AL) (CU) rod

___ 600A apparatus bushing with (AL) (CU) rod

___ Automation accessories