PCB Piezotronics IMI SENSORS 684a16, Installation And Operating Manual

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Installation and Wiring 

The 684A1/684A4 Enclosure is designed for use in conjunction with the Series 683A Panel Meter/Controller. The 
Enclosure can be located near the machine that needs monitoring. Depending on the Enclosure

’

s configuration, 

up to 8 sensors can be connected to the internal terminal blocks for interface to the Panel Meters/Controllers. The 
terminal blocks also provide for output connections including Raw Vibration, 4-20mA Retransmit, and Alarm/Alert 
Relays. 

Establish an easily accessible location for installation and keep in mind where the cabling will be oriented. Once 
the unit has been mounted, begin making appropriate connections for the interface cables. 

All user connections are made to the terminal blocks (Fig.1) attached to the inside rear panels of the unit through 
cord grips located on the bottom of the enclosure. The larges cord grip on the Enclosure should be used for 
power connection, all other cord grips are used for sensor and signal interface.  

Observe the labels on the terminal blocks when making connections. These labels identify the Panel 
Meter/Controller interface where #1 is the TOP ROW LEFT METER, #2 is the TOP ROW RIGHT METER, #3 is 
the SECOND ROW FROM TOP LEFT METER, and so on. Each Sensor Input has three connections, which are 
made on the terminal strip; one for the signal/power (typically red wire, +), another for ground (typically black 
wire), and the third is for the shield (typically a drain wire, SHIELD GND). 

Panel Meter/Controller Power is connected to the respective terminal block located in the lower middle position. 
Line, Neutral, and Earth Ground are connected to this block. Earth Ground should also be connected to the spade 
lugs located on the two bottom screws that hold the terminal block mounting bracket.  

The output connections from the terminal blocks consist of Raw Vibration, 4-20mA Retransmit, Alert (typically 
SP1) and Alarm (typically SP2) Relays. All of these connections should go to process control/monitoring 
equipment, additional signal conditioners, and machine diagnostic tools. 

To install the wires, unscrew the terminal block so that enough room exists to insert a wire stripped of its 
insulation. Insure that no bare wire is exposed and tighten the screw on the terminal block to hold the wire in 
place.  

To install Earth Ground to the spade lugs, remove the lugs by first unscrewing the terminal block mounting 
bracket. Insert the Earth Ground wire into the lug and crimp using a crimping tool or a set of pliers. Reinstall the 
lug to its original location. Note that all terminal block mounting bracket screws do not need to be removed during 
Earth Ground installation. It is recommended that only the screws holding the lugs to the bracket be removed. 

Regardless of ordered options, all Enclosures come equipped to electrically accommodate eight meters. 
Therefore, some terminal blocks may be unused. 

WARNING 
 
 

AC and DC input signals and power supply voltages can be hazardous. DO NOT 

connect live wires to screw terminal plugs, and DO NOT insert, remove, or handle screw 

terminal plugs with live wires connected.