Introduction

This bulletin explains how to install a control bus, which is used to connect the Powerlink remotely operated circuit breakers and the Powerlink electronics.

Components of a Control Bus

The Powerlink system uses one or more NF Powerlink control busses attached to interior rails in a panelboard. The control busses are used only with NF panelboards manufactured August 1, 2000 or later because these panelboards have holes on the interior rails for mounting Powerlink control busses. The date code is located on a yellow sticker on the deadfront and also on the UL label located on the interior rail. The first number represents the year, the second number represents the week of the year, and the third number represents the day of the week (Monday = 1, Tuesday = 2, Wednesday = 3, etc.). NF panelboards with a date code of 00 31 2 or later are furnished with the above referenced mounting holes.

A control bus has a series of bus connections, or poles, which varies in number and is selected based on the size and type of the panelboard. Every control bus has a section containing one secondary bus interconnect cable connection, three LEDs, and vertical bus connections (see Figure 1). The vertical bus connections are used to connect the power supply, controller, or the secondary address selector accessory.

Control Bus

When installing control busses in a standard NF panelboard, there will be both left and right control busses. On an eighty-four space panel there are up to four control busses. The size of the panelboard used will determine the control bus size, and the number of poles will determine whether installation of both left and right control busses is needed (see Table 1 or Table 2). The left control bus is mounted to the left interior rail, while the right control bus is mounted to the right interior rail.

For a column-width panelboard, both control busses are mounted to the same interior rail. The left control bus is inverted and mounted at the bottom of the interior rail, while the right control bus is mounted at the top.

Control Busses for Standard NF Panelboards

Panelboard Interior Size	Total Powerlink Pole Spaces	Available Powerlink Pole Spaces	Control Bus Catalog Number	Mounting Location
30 circuit	24	12 or less	NF12SBLG3	Left
		13–24	NF12SBLG3	Left
		13–24	NF12SBRG3	Right
42 circuit	36	18 or less	NF18SBLG3	Left
		19–36	NF18SBLG3	Left
		19–36	NF18SBRG3	Right
54 circuit	42	21 or less	NF21SBLG3	Left
		22–42	NF21SBLG3	Left
		22–42	NF21SBRG3	Right

Control Busses for Column-width NF Panelboards

Panelboard Interior Size	Total Powerlink Pole Spaces	Available Powerlink Pole Spaces	Control Bus Catalog Number	Mounting Location
30 circuit	24 (30)*	12 or less	NF12SBRG3	Top
		18 or less	NF18SBRG3	Top
		21 or less	NF21SBRG3	Top
		22–24	NF12SBRG3	Top
		22–24	NF12SBLG3	Bottom
		(22–30)*	(NF18SBRG3)*	(Top)*
		(22–30)*	(NF12SBLG3)*	(Bottom)*
42 circuit	36 (42)*	12 or less	NF12SBRG3	Top
		18 or less	NF18SBRG3	Top
		21 or less	NF21SBRG3	Top
		22–36	NF18SBRG3	Top
		22–36	NF18SBLG3	Bottom
		(22–42)*	(NF21SBRG3)*	(Top)*
		(22–42)*	(NF21SBLG3)*	(Bottom)*

LED Function and Operation

The three LED lights on a control bus indicate various network communications (see Figure 2). The LEDs are different colors and blink when data has been received or transmitted and whether the processor is active and functioning. LED Activity lists the LEDs and how they function.

LED Activity

LED	Color	LED Activity
RX	Green	When flashing, it indicates that data is being received.
TX	Yellow	When flashing, it indicates that data has been received and a response has been sent.
CPU	Red	When flashing concurrently with the RX LED, it indicates that the processor is active and data has been received.
CPU	Red	If the CPU LED flashes a steady on/off pattern with 0.5 seconds between each flash, the control bus is not receiving data.

NOTE: Every 30 seconds, all of the LEDs will flicker concurrently for 1 second. This activity indicates that the controller is searching for other control busses on the subnetwork.

NOTE: If a control bus does not receive communications from a controller after 10 minutes, the control bus will turn on all of its circuit breakers at a rate of one per second. Some third parties have turned off this feature.