Emerson 214A400, 214A401 Installation, Mounting, Connecting Slave ATS Annunciators, Cover removal

Serial Communications

Serial communications permits large amounts of information to be processed over a few wires. In the serial communications systems used by ASCO, each individual device in the system --- automatic transfer switch, bypass-isolation switch, ATS annunciator, etc. --- has a unique code, or address, that is assigned to it through DIP switches in the devices. According to the established ASCO serial communications rules, or protocol, each ATS annunciator and/or the network supervisor on the communication link “talks” to all automatic transfer switches and other elements being monitored on the link at the same time. They all “hear” what is being said, but only the device that is addressed responds.

Sending and receiving requests and commands is done over the same pair of twisted wires linked in a network fashion from one device to another to form the communication link, or highway. This physical configuration comprises a network in which only the addressed device is permitted to go on line and respond to an inquiry. With this serial communications system, a minimum number of wires can be used to link the elements together. Without serial communications, it would take considerably more wires to accomplish the same thing.

INSTALLATION

The ATS Annunciator has been tested and is ready to use. Installation simply requires mounting, connecting power and communication wiring, and setting DIP switches. When unpacking the unit, locate the loose parts which are supplied in a separate kit. The kits contain the following parts:

Master Kit 401091	Slave Kit 401092
label holder labels	label holder labels,
& 2 resistors	2 resistors, & ribbon cable

The Master ATS Annunciator can be readily identified by the front mounted key switch (to prevent unauthorized operation). You will find the key taped inside the back panel. Up to two Slave ATS Annunciators can be mounted directly above or below the Master. All three ATS Annun- ciators are then interconnected by means of ribbon cables. All external wiring for power and serial communication line connects to the Master ATS Annunciator. Observe the requirements of the National Electrical Code (especially Articles 725 and 800) and any local codes when interwiring.

Mounting

An Outline and Installation drawing (JS 387797) is included in the back of this manual. The two---part enclosure, which measures 10I wide x 6I high and 2I deep, is designed for mounting to the standard wall boxes listed on the drawing. After removing the front cover the hinged circuit board opens to the right to expose the mounting holes in the base.

Loosen four screws to remove the cover as shown in Figure 1. Remove four screws and remove the face plate. Then remove the two left standoffs and swing the hinged circuit board to the right as shown in Figure 2. You will find the key taped to the back panel. Run the power wires (and insulated ground wire) and communication cable (twisted pairs) through the center hole in the back of the enclosure, then to the right through the notch in the circuit board. Attach the ATS Annunciator to the wall box by using the mounting holes that line up. Swing the circuit board closed again. Reinstall the two standoffs and tighten them securely. Reinstall the face plate with four screws.

Connecting Slave ATS Annunciators

Connect the Slave ATS Annunciator(s), when used, to the Master. Remove the adhesive labels from the slotted openings as shown in Figure 2.

Then run the ribbon cable between ATS Annunciators and plug each end into the adjacent sockets. Two Slaves may be connected to one Master either by above and below arrangement or two below arrangement. See the Outline and Installation drawing for details.

face plate screws

cover	cover screws
Figure 1.	Cover removal.

power wires, insulated ground wire,	hinged circuit board
and communication cable

slotted opening for ribbon	standoff
cable and removable label		face plate

Figure 2. Hinged circuit board (Master).

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