Introduction
Before You Begin
5
1. Equipotential bonding of the installation site,
2. Minimizing static hazards associated with the underground storage of flammable liquids, and
3. Protection of the system against lightning strikes and any other source of possible electrical surges caused by
electrical railway systems, high voltage direct current facilities and the like.
EQUIPOTENTIAL BONDING
Consult any local regulations prior to installing a Mag-FLEX Probe into any tank. The Mag-FLEX is supplied with an
approved process connection.
The intrinsically safe circuit in the TLS Monitoring System is derived from a fuse protected zener diode intrinsic
safety barrier. This type of explosion protection requires that the intrinsically safe electric circuit is referenced to the
safety ground associated to the mains circuit. If the site has a submersible pump (DIN/EN 15268) connected to
the same mains safety ground as the TLS Monitoring System Console and it is installed in a metallic riser of a
metallic storage tank, the zener diode barrier must be referenced to the same earth (safety) ground.
The body of the probe can be directly bonded to the tank structure via a 4mm
2
cable (not supplied) using the
grounding screw and saddle clamp on the probe housing.
MINIMIZATION OF ELECTROSTATIC HAZARDS
Consult any local regulations prior to installing a Mag-FLEX probe into any tank. Veeder-Root supplies approved
process connections for installations where direct connection between the probe body and tank structure is
required (see Probe Installation Using Process Connection instructions below).
The Mag-FLEX probe housing complies with the 500 volt electrical strength requirements in IEC/EN 60079-11. In
addition, the probe housing should be equipotentially bonded to the tank structure via a 4mm
2
wire (not provided)
and the saddle clamp and grounding screw on the probe housing.
All TLS Consoles provide an alarm if either of the two wires to the Mag-FLEX probe is disconnected or short
circuited due to a malfunction.
If a probe must be serviced or replaced, observe any required relaxation time prior to opening any covers and
removing the probe.
LIGHTNING AND SURGE PROTECTION
Consult any local regulations prior to installing a Magnetostrictive Probe into any tank. Local rules or regulations
may require surge arrestors when installing equipment that crosses from a less restrictive zone, e.g., zone1 to zone
0 independent of the risk assessment. When required Veeder-Root can supply appropriate surge protection
devices.
In locations where the intrinsically safe cables or circuits are considered to be at risk of developing hazardous
potential differences within Zone 0, an external surge protection device may be needed. Perform the lightning risk
analysis to determine if surge protection is required, and if necessary, the surge protector shall be installed in
accordance with IEC/EN 60079-25 and IEC/EN 60079-14. Reference Figure 2 and Figure 3 for mounting
locations for a surge protector.
When they are deemed necessary, the surge arrestor shall either be a certified in-line device or a simple apparatus
conforming to the requirements of EN 60079-14: Electrical installations design, selection and erection. Only gas-
discharge type surge protectors that comply with Clause 12 of IEC/EN 60079-25 are acceptable. Additional
installation requirements for surge protection devices are defined in Clause 12.3 of standard IEC/EN 60079-14.
