Rice Lake 320IS Plus Intrinsically Safe Digital Weight Indicator - Installation Manual - Manual (Page 17)

320IS Plus Installation Manual - Installation 11
A separate conduit system is recommended for installation. The type suggested for this application is 3/4" rigid
steel conduit with pull boxes located at required intervals. The conduit provides additional noise protection for
the low-level signals, while automatically complying with the requirements for two-inch separation between
intrinsically safe circuits and other electrical cables. Conduit seals are necessary where a gas tight seal is required
between hazardous area and safe area.
2.3.2 AC Power Wiring
Standard units are powered by an FM-approved power supply. 100–240 VAC into RLWS IS-EPS-100-240
Intrinsically safe DC output power supply (PN 72713) is recommended.
See the IS-EPS-100-240 Power Supply Instruction Sheet (PN 79820) for information on wiring and power
specifications.
2.3.3 Battery Option
The optional battery pack provides an intrinsically safe battery that can replace the power supply. The battery is
approved for use in hazardous environments and limited use operations such as bench scales and platform scales.
A low battery error message will display to indicate that the battery needs to be recharged. Always charge the
battery overnight. The yellow indicator light will remain on until the battery is charged at about 70%, at which
point the indicator light will turn green and the charger will switch to float charge mode. Once the light turns
green, the battery requires another 3 hours on float charge before the battery is fully charged.
To keep battery at full capacity, it is recommended to leave the battery connected to the charger, in float
charge mode, until ready to use. The battery can remain on the charger in float charge mode indefinitely
without damaging the battery. See Battery Charging Instruction Sheet (PN 96567) for instructions on
charging the battery.
While connected to the DC battery pack with the indicator off, the 320IS still draws a small amount of
current that will shorten battery run time. To preserve battery life, disconnect the battery when not in use.
2.4 Cable Connections and Installation
The following sections contain information on cable connections and installation for the 320IS Plus .
Intrinsically safe cables are specified by control drawing. All cables must have appropriate internal
inductance and capacitance. Cable lengths are based on group classifications.
Figure 2-2. Metal Cord Grip
Load Cell Size Quantity of cells Operating Time
350
 load cell
1 40 - 50 hours
4 35 - 40 hours
700
 load cell
1 45 - 55 hours
4 40 - 50 hours
Table 2-2. Estimated Battery Operating Times
Note
Note
Note