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Outline Grounding Washer, Electrical Equipment Bond (WEEB) Acme Cable Clips Acme Conduit Entry (ACE) Questions
Bonding & Grounding
Grounding Terms Equipment Grounding: The National Electrical Code (NEC) requires that all noncurrent-carrying exposed metal on equipment and components be grounded. Grounded: Connected to the earth or to a conducting body that serves as earth through a ground connection or connections. Grounding Electrode Conductor: Bare copper wire connecting grounded conductor and/or equipment grounding conductor to the grounding electrode. Grounding Electrode: A conductor that is firmly embedded in the earth, and can thus function to maintain ground potential on the conductors connected to it.
NEC 690.43 Exposed non-current carrying metal parts of module frames, equipment and conductor enclosures shall be grounded in accordance with 250.134 or 250.136(A) regardless of voltage. NEC 250.136 Under the conditions specified in 250.136 (A) and (B), the normally non-current-carrying metal parts of the equipment shall be considered grounded. NEC 250.136 (A) Electrical equipment secured to and in electrical contact with metal rack or structure provided for its support and connected to an equipment grounding conductor by one of the means indicated in 250.134...
Previous Approaches Direct burial lug Intended to be used on conductive surface. Lug is rated to hold up to a #6 AWG copper wire, but common combinations of lug and mounting screw would only be equivalent to #10 AWG. Stainless steel screw should not be used as a conductor. Requires surface preparation to install properly. Introduces point of susceptibility to corrosion.
Previous Approaches to Grounding Star washer between module frame and rail Washers may compress into a flat shape. It can scrape the surface, but cannot reliably penetrate anodizing or clear coat finishes. Not tested to any standard. #10 AWG wire on stainless screw between stainless washers. Small wire size which is labor intensive and does not meet code for damage protection. May be installed incorrectly.
Concerns About Grounding From AHJ s/installers Loosened nut and/or screw where a ground wire or ground lug or terminal is installed. Loosened Clamp. Insufficient ampacity in the screw threads due to limited thread contact. Insufficient penetration of a non-conductive frame coating such as anodizing using a star washer. Corroded connections.
Pictures of Poor Installations Improperly Installed Grounding Hardware Dry-location Lug Rusting Outdoors Dissimilar Metals
WEEB Solution
WEEB Solution Washer, Electrial Equipment Bond Why WEEBs? How can one quickly and effectively ground PV module frames and mounting rail. Most frames and rails are anodized aluminum and therefore non-conductive. Preferred wiring is copper which is electrochemically incompatible with anodized aluminum. Installations are outdoors and exposed to the elements.
How the WEEB works Thin stainless steel washer inserted between module frame and mounting rail. Does not affect structural strength. Stainless steel is corrosion resistant and durable in outdoor applications. Specially designed teeth penetrate any module frame coating for excellent conductivity. Tested & Listed to ANSI/UL467, equivalent to #6 AWG wire for use in the US and Canada. Now also listed to ANSI/UL1703 for use in the US and Canada.
The WEEB teeth pierce through the anodized coating to obtain contact between the solar module and mounting frame Use WEEB Lug 6.7 to connect bonded structure to equipment ground conductor Solar Module Frame WEEB-6.7 WEEB-9.5 Mounting Frame
Embedded Teeth Marks Point of electrical connection
Benefits of the WEEB Module bonded to the rail Rail current carrying capability is equal to 10-20x that of a 6 AWG wire. EX: Pro-Solar = 10x EX: DPW = 20x DPW Cross Section of Rail
Additional Benefits Enhanced lightning protection ANSI/UL 467, #6 AWG, tested to carry 1530 Amps for 6 seconds Environmental tests with no measurable degradation Fails in safe manner Speeds up installations Lowers installed cost of solar
WEEB Details One time use Apply anti-seize before bolting down Not compatible with self drilling screws Lugs and Jumpers torqued to 10 foot pounds WEEBs torqued 10-15 foot pounds
Torque Specs Use anti-seize! Use a torque wrench! Why? Friction between the nut and bolt reduces clamping force. Stainless steel is prone to galling, adding to friction. Using anti-seize is a best practice for reducing friction and ensuring that hardware does not seize. The bolt and nut compresses the hardware more easily when anti-seize is used. Using a torque wrench is the only way to make sure the specified torque is being applied.
Environmental Degradation Testing Embed Test High Current Test -1530A for 6 sec. Salt Bath Test -200 cycles Humidity Freeze -10 cycles Thermal Cycling Test -18 yrs. / 80ºC to -20ºC High Temperature Accelerated Life Test -38 years
TESTING: High Current Test
Close Up View of WEEBs
Module Frame Compatibility Compatible with various cross-sections of module frames. The WEEB teeth need to be positioned completely under the edge of the module frame. Boxed Frame C - Frame
WEEB Compatibility Module frames like those shown here may have a ridge or lip on the bottom edge of the frame that would prevent the WEEB teeth from fully embedding. Shown here is an example of a lip that will prevent the WEEB teeth from properly penetrating the module frame. This type of frame is not compatable with the WEEB. Important Note: Inspect each module frame used with a WEEB to ensure that the bottom mounting face of the frame is flat, and that there are no hinderances to embedding the WEEB teeth. Do not use a module with a frame that prevents the WEEB teeth from fully embedding. Shown here is an example of a groove that will prevent the WEEB teeth from properly penetrating the module frame. This type of frame is not compatable with the WEEB.
Schott Application Schott Poly: 230, 225, 200, 217, 210, 202, 195 The teeth are not embedded. Without the contact from the module frame to the rail it is unsafe un-bonded connection.
Top Mounting Application
How Many WEEBs? Rule of thumb: 4 teeth per module
Pre-assembly
Solutions for the Enphase Microinverter Listed by CSA Recommended by Enphase WEEB PMC, KMC, CMC, SMC, DMC Please see application note on the website for details http://www.enphaseenergy.com/downloads /EnphaseAppNote_WEEB_Installation.pdf
Bottom Mounting Applications Ground Mount, Pole Mount, Bolted Connections
WEEB- 9.5 & 9.5NL WEEB 9.5 Use with 1/4 up to 5/16 hardware Fits into a 3/8 clearance hole Use 2 WEEBs per module WEEB 9.5NL Use with up to 3/8 hardware Both for use with Pole mounts, ground mounts and bolted connections
WEEB-9.5 Application Solar Module Frame 0.375 /9.5mm hole WEEB-9.5 Thick washers for use with 1/4 or 5/16 fasteners. Mounting Frame OK
WEEB-9.5NL Application OK WEEB-9.5 NL Mounting Frame When fastening with 1/4 or 5/16 fasteners, use thick flat washer to spread the embedding force. For 3/8 fasteners, use regular washers.
Top of Pole Assembly Placement of WEEB: 9.5 & 9.5NL s
WEEB-9.5NL
WEEB-9.5
Lugs Tin plated copper lug 1/4 hardware Used with WEEB-6.7 Torque to 10 ft lb with anti-seize Allows for: #6 AWG or (2) #10 AWG or (2) #12 AWG wire bare copper or stranded wire
Lugs Continued Lug-6.7 for use with 1/4 hardware Lug-8.0 for use with 5/16 hardware
Application - Rail
Application - Module
Bonding Jumpers Use Details Creates electrical bond across mechanical splices Tin plated copper braided cable WEEB-6.7 and 1/4 hardware Torque 10 ft lb Equivalent to #6 AWG
Bonding Jumpers Continued Maintains electrical bond across thermal expansion joints.
Application
Codes & Standards
Servicing an Array NEC Code (Sec. 60.8) states, where the removal of equipment disconnects, the bonding connection between the grounding electrode conductor and exposed conducting surfaces in the PV source or output circuit equipment, a bonding jumper shall be installed while the equipment is removed.
Questions from Inspectors Sending plan in for approval including grounding. Printing out the instruction manuals for the racking, WEEBs, and modules.
Wire Management
Acme Cable Clips Simplify wire management Clean aesthetic for Solar PV Prevents damage to cable insulation Corrosion resistant stainless steel
Acme Cable Clips Acme Cable Clip USE-2 Wire & PV Wire 2 wires at 5.0 to 5.7mm 1 wire at 5.0 to 7.2mm Holds 1 or 2 wires Corosion Resistant Stainless Steel Easy tab for installation Acme Cable Clip PV PV Wire 2 wires at 6.8 to 7.2mm 1 wire at 6.8 to 8.0mm Holds 1 or 2 Wires Prevents damage to cable insulation Dual wire compartments
Acme Cable Clip: ACC-R2 Wire management attachment to the rail ProSolar Roof Track SnapNrack Ironridge XRS & XLS Unirac Solarmount DPW Power Rail Holds trunk cable and drop cable for Enphase M190, D380 Wire diameter 9.3 11.0mm
Acme Cable Clips: ACC-R4 Securely attach to a variety of rails: ProSolar Roof Track SnapNrack Ironridge XRS & XLS Unirac Solarmount DPW Power Rail Holds 1 to 4 PV wires 6.8 7.2 mm in diameter
Conduit Entry
Acme Conduit Entry (ACE) Simple array to conduit transition Polycarbonate Makrolon: High Temperature Rated 125ºC NEMA 3R rated Listed to UL 1741 US/CA Standards
Acme Conduit Entry Configurations Rail Mounted Top of Pole Low Profile: 10.07 x 7.51 x 3.15 Volume of Box: 112 cubed
Configurations Pass Through or Combiners, up to 4 strings, are available.
Thank You Contact for Technical Questions: Paul Kovalov paul@we-llc.com (845) 247-4708 www.we-llc.com