The National Electrical Code (NEC) mandates specific requirements for junction box installation, with the most important being the rule of accessibility. Every junction box housing a splice or termination must remain permanently accessible for inspection, maintenance, and repair. This means you cannot permanently bury a box behind drywall, plaster. Instrumentation Junction Boxes (JBs) are very important parts of control and automation systems. JBs are used often in fields like oil and gas, petrochemicals, power production, and water treatment. One of the smaller changes made by Amendment No 1 was the introduction of maintenance free junction boxes. Item (vi) was added to regulation 526. 3:. Principle: Prevents sparks/hot surfaces in normal operation by limiting temperature rises and providing secure terminations/clearance. Construction: Typically robust stainless steel or GRP with adequate internal space and robust terminals. Always install your boxes where you can reach them later.
[PDF Version]