Cut Sheet
Class I, Division 1 and 2, Groups B, C, D
Class II, Division 1 and 2, Groups E, F, G
Class III
NEMA 3, 4
Enclosures and Junction Boxes
EnclosurEs and Junction BoxEs: Hazardous location conduit outlEt BoxEs
Visit our website at www.appletonelec.com or contact us at (800) 621-1506.
© November 2011
501
GR Conduit Outlet Boxes
Explosionproof, Dust-Ignitionproof
UNILETS
®
for use with Threaded Metal Conduit. Furnished with Internal Ground Screw and O-Ring.
Hub Type
Conduit Size
(Inches)
Cover Opening
Inches/Millimeters
Volume
Capacity
in
3
/dm
3
Form
Number
Catalog Number
Malleable Iron
Body With
Aluminum Cover
Aluminum
Body with
Aluminum Cover
GRCA
1/2 3.38/85.9 18.0/0.29 1 GRCA50 GRCA50-A
3/4 3.38/85.9 18.0/0.29 1 GRCA75 GRCA75-A
GRLA
1/2 3.38/85.9 18.0/0.29 1 GRLA50 GRLA50-A
3/4 3.38/85.9 18.0/0.29 1 GRLA75 GRLA75-A
GRTA
1/2 3.38/85.9 18.0/0.29 1 GRTA50 GRTA50-A
3/4 3.38/85.9 18.0/0.29 1 GRTA75 GRTA75-A
Dimensions
Hub Size
(Inches)
Dimensions in Inches/Millimeters
A B C D E F G
GR Series, Form 1
1/2 3.75/95.3 2.44/62 2.88/73.2 0.75/19.1 0.81/20.6 2.25/57.2 1.25/31.8
3/4 3.75/95.3 2.44/62 2.88/73.2 0.75/19.1 0.81/20.6 2.25/57.2 1.25/31.8
1 3.75/95.3 2.44/62 2.88/73.2 0.94/23.9 0.94/23.9 2.25/57.2 1.06/26.9
GR Series, Forms 2 and 3
1-1/4 4.50/114.3 2.69/68.3 3.56/90.4 1.19/30.2 0.88/22.4 2.75/69.9 1.13/28.7
1-1/2 5.75/146.1 3.75/95.3 4.81/122.2 1.38/35.1 0.94/23.9 4.06/103.1 1.50/38.1
2 5.75/146.1 4.00/101.6 5.06/128.5 1.63/41.4 1/25.4 4.25/108.0 1.25/31.8
1-1/4”=Form2
1-1/2”&2”=Form3
In Class I, Division 1, Group B atmospheres, all conduit runs must have a sealing fitting (not supplied) field-installed adjacent to the enclosure.
Other covers available—see GR and GRF Conduit Outlet Box Covers page. Order separately.
For malleable iron body and cover, add suffix -M.
Form number designates body and matching cover sizes. To order body without cover, add suffix -LC to catalog number.