YSI 6500 Environmental Process Monitor - Manual (Page 19)

Installation Section 2
2.5.4 GROUNDING INFORMATION
This section contains important installation information regarding grounding of the 6500 Monitor
and 6-Series Sonde. The sonde is powered by the 6500 Monitor or by batteries (depending on
which sonde you have chosen) and will be operated with a “floating” ground reference. This
requires that the sonde not be individually grounded. Grounding the sonde individually will
cause a “ground loop”; i.e. one conductor of the sonde output grounded common to both the
sonde and the meter. Grounding the sonde will cause significant performance problems with the
sensors and likely result in erroneous readings.
IMPORTANT!
Do not ground the sonde body.
2.5.5 SAFETY ISSUES
The electrical system must be grounded to avoid possible electrical shock or damage to the
equipment.
WARNING!
Turn off all power and assure power “lockout” before servicing to avoid contact with electrically
powered circuits.
To avoid possible electrical shock, do not touch other circuit components when making
adjustments to the 6500 Monitor circuit board. Disconnect external power to the unit before
connecting or disconnecting wiring.
2.5.6 LIGHTNING AND SURGE PROTECTION
Surge protectors are strongly recommended to protect from secondary surges and lightning on
outdoor installations.
Surge suppression devices should be located on the AC line supplying power to the 6500 Monitor
and any signal lines connecting the 6500 Monitor to alarms, a SCADA or other data collecting
device.
AC line voltage surge suppressors protect field equipment on any AC line to ground from damage
due to electrical transients induced in the interconnecting power lines from lightning discharges
and other high voltage surges. The unit should include noise filtering, common mode and normal
YSI Incorporated 6500 Environmental Process Monitor 15