YSI 6500 Environmental Process Monitor - Manual (Page 20)

Installation Section 2
mode suppression and nanosecond reaction time. Surge suppressors should be internally fused to
remove the load if the unit is overloaded or the internal protection fails.
Signal line suppressors protect 4-20 mA DC current loops, low voltage signals and relay outputs
from damage due to electrical transients induced in the signal lines from lightning discharges or
nearby electrical devices. Signal line suppressors should be installed at each end of an analog
loop. Relay outputs should be protected at the receiver end. Signal line suppressors should
consist of a three-element gas tube followed by metal oxide varistors and suppressor diodes. The
protective elements should be matched such that high-energy surge voltages trigger the gas surge
arrester, while low energy or surge voltages affect the MOV’s and suppressor diodes.
Lightning protection devices should be located as close to the sonde and monitor as possible and
wired in accordance with the National Electric Code in approved watertight enclosures. If the
distance between the sonde and the 6500 Monitor is less than 100 feet, only one protector per line
is needed, otherwise lightning protection should be installed at both ends of the wiring runs.
IMPORTANT NOTICE
This or any other installation procedure can not protect against a direct lightning strike. YSI
Incorporated cannot accept liability for damage due to lightning or secondary surges.
2.6 SEALANTS, DESICCANTS AND SECURING THE MONITOR
Since the 6500 Monitor, Breakout Box(s) and/or Junctions Box will likely be subjected to
environmental conditions that promote formation of condensation, it is very important to follow
the instructions below before securing the cover to your unit(s). This will prevent damage to the
electronic components within the Monitor and extend the life of the monitoring system.
Enclosed with shipment of every 6500 Environmental Monitoring System is industrial
encapsulant (conduit sealer), in a cartridge for your convenience. After all wiring is complete
apply the sealant to the conduit openings from the inside of the 6500 Monitor, Breakout Box
and/or Junction Box if applicable. This will help prevent moisture from entering the inside of the
6500 Monitor from conduit that was used for AC power cable or signal cables.
Note: If any of the conduit fittings were not used in the installation, remove the fitting and
replace with a 3/4” knockout plug provided with the unit. Two knockout plugs are provided.
Also enclosed with the 6500 Monitor is a box of desiccant packs. After all wiring is completed
and sealant applied, place two desiccant packs inside, near the bottom right of the Monitor before
securing the cover. This desiccant will consume any moisture captured during the closure to
provide a low humidity environment within the Monitor.
To complete the installation secure the cover of the 6500 Monitor using the four mounting screws
that you removed while doing the wiring operations. Note that the cover contains a captured
rubber gasket that provides the weatherproofing. Make certain that the gasket is in place and not
damaged. Check to make certain that the large blue ribbon cable is not trapped in the gasket
YSI Incorporated 6500 Environmental Process Monitor 16