B-Line Eaton series imperial cable tray and ladder, 4" Height, 33.539" Length, 30" Width, Series 2-5 vertical inside bend, Aluminum, 45° Angle, 36" Ra

A vertical inside bend carries the tray run up or down at an angle while keeping the cables on the inside of the turn, so the bend radius supports the conductors instead of pinching them. B-Line part 4A-30-45VI36 turns the run through 45 degrees on a 36 inch radius. Use it where the tray has to follow a ramp, a ceiling step, or a drop into equipment rather than change direction horizontally.

The radius sets the minimum bend the cables have to take. This fitting is a 36 inch radius, which is the largest of the common tray radii and is what you want for large power conductors or fiber with a generous minimum bend radius. If your cable allows a tighter turn, a 12 inch or 24 inch radius fitting of the same width takes up less space in the ceiling. Mixing radii in one run is fine as long as each fitting matches the tray width.

Allow 33.539 inches of length for the fitting itself, measured along the run, plus your straight sections either side. It is 30 inches wide and 4 inches deep at the rails. Lay that out before you set your trapeze hangers, because a 36 inch radius fitting eats more ceiling than a small radius elbow.

The fitting carries CSA certification, so it can be specified on work inspected to Canadian electrical code.

What you are ordering is the bend itself, part 4A-30-45VI36. Splice plates, hardware, hold-down clamps and hangers are separate line items, so add the connections for both ends of the fitting to your order.

It depends which way the cables sit relative to the turn. An inside bend, like this one, is used where the tray turns so the cable load presses into the curve, typical of a run dropping away from a high point. An outside bend is used for the opposite geometry, where the run rises and the cables are carried around the outer face. Ordering the wrong one leaves the tray flanges facing the wrong direction and it will not bolt into the run.

At 9.2 lb it is a one-man lift on a ladder, which is the practical advantage of aluminum over steel tray fittings of the same size. Weight still has to be added to your support load calculation along with the cable fill.