Page 9

Reference Section
Sensors mounted with good electrical contact to a well-grounded surfaces (preferred)
1. 25-pin D-sub connector grounding: The encoder's connector shell must be in intimate, electrically conductive contact with the customer-
supplied mating connector, which must be isolated from the controller's ground. If a customer-supplied shielded cable connects the encoder
to the controller, then the shielding on the customer-supplied cable must be isolated from the controller's ground.
2. The sensors’ mounting surfaces must have a low impedance (DC/AC) connection to ground. The encoder sensors’ mounting surfaces may have
to be masked during painting or anodizing to insure good electrical contact with the sensors.
For Mercury 3000Si Dual Axis Averager encoder systems to operate reliably, it is essential that the sensor and cable shield are ground-
ed properly according to the following instructions. The diagrams below show how to make the connections when the encoder's con-
nector is plugged into the customer's controller chassis. If a customer-supplied extension cable is used, it should be a double shielded
cable with conductive connector shells and must provide complete shielding over the conductors contained within it over its entire
length. Furthermore, the shields should be grounded at the connection to the controller chassis the same way as the encoder connec-
tors in the diagrams below.
Note: For best performance, isolate encoder shield from motor cable shields and separate encoder cable as far possible from motor cables.
Sensors mounted to a surfaces that are grounded through bearings or poorly-grounded surfaces, or non-conducting surfaces
1. 25-pin D-sub connector grounding: The encoder's connector shell must be in intimate, electrically conductive contact with the customer-supplied mating
connector, which must be connected to the controller's ground. If a customer-supplied shielded cable connects the encoder to the controller, then the
shielding on the customer-supplied cable must be connected to the controller's ground. The controller must be grounded to earth at the point of installation.
2. The encoder sensors must be mounted so that they are electrically isolated from ground.
Mercury encoders require a minimum of 4.75V DC continuously. When designing circuits and extension cables to use Mercury encoders, be sure to
account for voltage loss over distance and tolerances from the nominal supply voltage so that at least 4.75V DC is available to the Mercury encoder
under all operating conditions. The input voltage should not exceed 5.25V DC.

Grounding Instructions for Mercury 3000Si Dual Axis Encoder Systems

Recommendations for Power

Inner Shield: Insulated from outer shield,
sensor and connector housing. Connected
to circuit common internally.
Outer Shield: Connect to sensor
and connector housing.
Electrically conductive
mechanical connection
(as supplied by MicroE
Systems).
Do not ground shroud.