sunpower junction box installation guide 1 of 8 530166

SUNPOWER JUNCTION BOX INSTALLATION GUIDE 1 of 8530166 – METAL ROOF TRANSITION JUNCTION BOX

1. Before installing the metal pan through which the j-box will be installed, drill or punch a hole (Ø1-7/16” min., Ø1-1/2” max.) for the conduit centered between the ribs (Fig. A1). Make sure it will not contact any obstructions, such as the microinverter on the module. Ensure that the hole location will not hit a rafter.

2. Apply a ring of sealant surrounded by an inverted U-shape of sealant around the hole on the underside of the pan (Fig. A2). Use a SunPower-approved silicone or butyl sealant specified for use on rooftops & flashings. Take a photo of applied sealant before placing pan for JCO submission.

3. Install the pan onto the roof. 4. Using the hole made in the pan in as a guide,

continue the hole through the roof using a hole saw the same diameter as the hole in the pan (Ø1-7/16” min., Ø1-1/2” max.).

5. Remove the lid from the box and drill a hole in the side wall of the box for your intended fitting (Fig. A3). The included cable gland is a 3/4” trade size fitting and requires a 1-1/8” diameter hole. The hole should be located on a centerline that lies along the bottom tips of the two ribs on the side of the box. Install fitting in hole.• See Important Requirements section for fitting

specs and torque values.6. Install the fittings for the conduit into the bottom

of the box. Multiple conduit details are possible depending on installation needs. See Fig. D1 through Fig. D5. • Fittings larger than the hole can’t be pre-

installed (for example rigid conduit hubs) or must be installed from the attic side (for example some larger NM cable clamps).

7. Remove the liner paper from the bottom of the box, exposing the sealant tape (Fig. A4).

MIN. Ø1-7/16 in MAX. Ø1-1/2 in

Use straight edge against box ribs to mark line on the side of box

Fig. A1. Drill hole through metal pan.

Fig. A2. Apply sealant on underside of roof pan.

Fig. A3. Drill hole in box for fitting.

Remove liner before attaching to roof

Fig. A4. Prep for installation to roof.

©2020 SunPower Corporation. All Rights Reserved. SUNPOWER and the SUNPOWER logo are trademarks or registered trademarks of SunPower Corporation in the U.S. and other countries as well. Specifications included in this document are subject to change without notice. 537445 RevA

Ø1-1/8”

8. Insert the conduit stub through the hole in the roof being sure to align the arrows inside the box pointing upslope. Press the box against the roof to ensure the sealant tape makes solid contact with the metal roof pan.

9. Use two #12 metal-to-wood screws to attach the box to the roof through the holes in the bottom of the box (Fig. A5). The screws should be tight enough to slightly compress the sealant tape on the bottom of the box.

10. Pass the trunk cable and ground cable into the junction box through the gland. Strip back the outer trunk cable jacket to expose the two internal conductors. Splice the circuit conductors and ground cable to NM cable or other building interior wiring solution that is NEC compliant.

11. Reinstall the junction box lid (Fig. A6). Snug tight all four screws in a crisscross pattern to ensure compression of the lid gasket, to the value specified in the Torque Value table.

Fig. A5. Attach to roof.

Fig. A6. Re-install lid.

Installation Requirements• When using the included cable gland (PN 531969,

marked Heyco, SMCG 3/4 NPT), follow these parameters:

• Only for use with Listed DG Cable by Enphase, type IQ Cable, 12 AWG.

• Torque values as specified in table at right.• When entering the box with a conduit fitting,

follow these parameters:• For 3/4” conduit, use Listed “Type 4” hub.• For 1” conduit, use Listed hub with Listed ABB

(Thomas & Betts) sealing ring, type 5304.• The junction or pull box is to be used in an

installation in which equipment is grounded by connection to metal raceway or metallic cable sheaths.

• When used as a pull box, installation shall be in accordance with Section 314.28 of the National Electrical Code, ANSI/NFPA 70. (per UL50 cl 10.6.4).

• Failure to follow the installation guidelines can result in water intrusion to the building structure.

Torque Values

Heyco SMCG 3/4 NPT, PN 531969:Locknut

80 in-lb

Heyco SMCG 3/4 NPT, PN 531969:Compression Nut

Until nut bottoms out

Junction Box Lid Screws 50 in-lb


SUNPOWER JUNCTION BOX INSTALLATION GUIDE

530166 – METAL ROOF TRANSITION JUNCTION BOX2 of 82 of 8


530167 – RAIL-ATTACHED GROUNDING JUNCTION BOX

1. Identify where the junction box will be installed.a. The junction box should be located under the

array at the final module along the trunk cable.b. The box location must not interfere with the

microinverter on the back of the module.c. You can mount the box “above” or “below” the

rail (Fig. B1).2. Remove the lid from the box and drill a hole in the

side wall of the box for your intended fitting (Fig. B2). The included cable gland is a ¾” trade size fitting and requires a 1-1/8” diameter hole. The hole should be located on a centerline that lies along the bottom tips of the two ribs on the side of the box. Install fitting in hole.• See Important Requirements section for fitting

specs and torque values.3. Install any additional fittings for the home run into

the sides of the box.• Do not mount conduit or glands to the box

cover.• Maximum allowable conduit size is 1”.

4. Fit the bracket lip into the top channel of the rail, and then tilt the junction box downward until both of its tabs click around and fully engage the rail (Fig. B3). The teeth on the bracket will dig into the rail, creating a bonded connection.

5. Manually squeeze each tab upward to verify full engagement (Fig B3).

Use straight edge against box ribs to mark line on side of box

Fig. B1. Allowable mounting locations.

Fig. B2. Drill hole in box for fitting.


Fig. B3. Attach bracket to rail.

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Ø1-1/8”

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6. Pass the home run cable into the box. Land the grounding wire in the lay-in lug mounted to the center stud inside of the box (Fig. B4). Tighten the lug screw to the value specified in the Torque Value table.

7. Pass the trunk cable into the junction box through the gland. Strip back the outer trunk cable jacket to expose the two internal conductors. Splice the circuit conductors to the mating conductors in the home run cable.

8. Reinstall the junction box lid (Fig. B5). Snug tight all four screws in a crisscross pattern to ensure compression of the lid gasket to the value specified in the Torque Value table.

Installation Requirements• When using the included cable gland (PN 531969,



• Torque values as specified in table at right.• When entering the box with a conduit fitting,

follow these parameters:• For 3/4” conduit, use Listed “Type 4” hub.• For 1” conduit, use Listed hub with Listed

ABB (Thomas & Betts) sealing ring, type 5304.• The junction or pull box is to be used in an




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Fig. B4. Land grounding wire in lug.

Fig. B5. Re-install lid.


530167 – RAIL-ATTACHED GROUNDING JUNCTION BOX

Torque Values

Heyco SMCG 3/4 NPT, PN 531969: Locknut

80 in-lbf

Heyco SMCG 3/4 NPT, PN 531969: Compression Nut



Lay-In Lug Wire Terminal (from UL 1741 Table 66.1)

18–10 AWG

35 in-lb

8 AWG 40 in-lb

6–4 AWG 45 in-lb

4 of 8


530168 – COMP SHINGLE ROOF TRANSITION JUNCTION BOX

1. Identify where the junction box will be installed.a. The junction box should be located under the

array at the final module along the trunk cable.b. The box must be located between rafters.c. Locating the box at the top of the array will

typically allow for easier wiring inside building.d. The box location must not interfere with the

microinverter on the back of the module.2. Using the flashing as a template, mark the area of

the shingle to remove for clearance around the junction box. The bottom of the flashing should align with or be slightly above the bottom edge of the shingle (Fig. C1 & Fig. C2). Insert the flashing under the shingle to test fit. Remove any interfering nails with a shingle ripper.

3. With the shingle notched and the flashing properly positioned, mark the conduit hole on the roof. Remove the flashing and drill a hole through the roof (Ø1-7/16” min., Ø1-1/2” max.) (Fig. C3).

4. Apply a ring of sealant surrounded by an inverted U-shape of sealant around the conduit hole on the roof (Fig. C3) and reinsert the flashing. Use a SunPower-approved silicone or butyl sealant specified for use on rooftops & flashings.

5. Remove the lid from the box and drill a hole in the side wall of the box for your intended fitting (Fig. C4). The included cable gland is a ¾” trade size fitting and requires a 1-1/8” diameter hole. The hole should be located on a centerline that lies along the bottom tips of the two ribs on the side of the box. Install fitting in hole.• See Important Requirements section for fitting

specs and torque values.6. Install the fittings for the conduit into the bottom

of the box. Multiple conduit details are possible depending on installation needs. See Fig. D1 through Fig. D5. • Fittings larger than the hole can’t be pre-

installed (for example rigid conduit hubs) or must be installed from the attic side (for example some larger NM cable clamps).

Use straight edge against box ribs to mark line on the side of box

Fig. C1. Mark top line for notch.

Fig. C2. Mark sides of notch and trim shingle.

Fig. C4. Drill hole in box for fitting.


Mark line on shingle across upper edge of flashing bumps

Mark lines across outer edges of flashing bumps

Trim upper shingle in this area

SealantMIN Ø1-7/16 in MAX Ø1-1/2 in

Fig. C3. Drill roof hole and apply sealant.

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Ø1-1/8”

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7. Remove the liner paper from the bottom of the box, exposing the sealant tape (Fig. C5).

8. Insert the conduit stub through the hole in the roof being sure to align the arrows inside the box pointing upslope. Press the box against the roof to ensure the sealant tape makes contact with the metal roof pan.

9. Use two #12 metal-to-wood screws to attach the box to the roof through the holes in the bottom of the box (Fig. C6). The screws should be tight enough to slightly compress the sealant tape on the bottom of the box.

10. Pass the trunk cable and ground cable into the junction box through the gland. Strip back the outer trunk cable jacket to expose the two internal conductors. Splice the circuit conductors and ground cable to NM cable or other building interior wiring solution that is NEC compliant.

11. Reinstall the junction box lid (Fig. C7). Snug tight all four screws in a crisscross pattern to ensure compression of the lid gasket to the value specified in the Torque Value table.

Fig. C6. Attach to roof.

Fig. C7. Re-install lid.Installation Requirements• When using the included cable gland (PN 531969,



• Torque Values as specified in table at right.• When entering the box with a conduit fitting,

follow these parameters:• For 3/4” conduit, use Listed “Type 4” hub.• For 1” conduit, use Listed hub with Listed

ABB (Thomas & Betts) sealing ring, type 5304.• The junction or pull box is to be used in an



• Failure to follow the installation guidelines can result in water intrusion to the building structure.


Remove liner before attaching to roof

Fig. C5. Prep for installation to roof.

6 of 8

Torque Values

Heyco SMCG 3/4 NPT, PN 531969: Locknut

80 in-lb

Heyco SMCG 3/4 NPT, PN 531969: Compression Nut




530168 – COMP SHINGLE ROOF TRANSITION JUNCTION BOX6 of 8



Fig. D1. Rigid Metallic Fitting Short Stub Detail (Preferred).

Fig. D2. PVC Fitting Short Stub Detail.

3/4” NM cable clamp

3/4” PVC female straight adapter

3/4” PVC knockout adapter bushing

Fig. D3. Flexible Non-Metallic Conduit (ENT) Detail.

3/4” ENT conduit

3/4” ENT straight adapter fitting

3/4” nylon locknut

Conduit to bring individual conductors to electrical box or conduit system.

RECOMMENDED CONDUIT TRANSITION DETAILS7 of 8

3/4” rigid female coupler

3/4” rigid male knockout adapter


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Fig. D4. Flexible Metal Conduit (FMC) Detail.

Fig. D5. PVC Fitting Long Stub Detail.

3/4” FMC Straight twist-in adapter fitting

3/4” metal locknut

3/4” FMC conduit

Conduit to bring individual conductors to electrical box or conduit system.


3/4” PVC male straight adapter

3/4” PVC female straight adapter

3/4” PVC locknut

3/4” PVC conduit

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RECOMMENDED CONDUIT TRANSITION DETAILS8 of 8

sunpower junction box installation guide 1 of 8 530166

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