Review Wiring Regulations; Non-Incendive Inputs And Outputs - Mettler Toledo Jagxtreme Installationsanleitung

JAGXTREME Division 2 and Zone 2/22 Installation Guide
Review Wiring
Regulations
Non-incendive Inputs
and Outputs
2-2 (7/03)
There are many methods that may be used to install properly approved equipment
within hazardous areas. In some cases, the field circuit characteristics (electrical
approval data) must be compared to those of the device connected to make sure the
combination is safe. In other situations, only a confirmation of a certain IP rating may
be required to connect the devices.
METTLER TOLEDO claims no expertise with respect to all the electrical regulations that
may be in effect at any specific location. You must refer to a national and/or local
electrical standards handbook for the safest installation possible that meets all required
standards.
If a specific input or output is rated non-incendive, then a list of the field circuit
parameters for that I/O will be given on the control drawing or certificate. If an approved
apparatus will be connected to a non-incendive input or output, then a comparison
must be made between the electrical field circuit parameters of both devices including
the connecting cable. These field circuit parameters include voltage, current,
capacitance, inductance and sometimes power.
The two devices must compare as follows in order for the wiring to be considered non-
incendive:
(Maximum voltage permitted) ≥ V
V
max
(Maximum current permitted) ≥ I
I
max
C (Input capacitance) + C
i cable
L (Input inductance) + L
i cable
The field circuit parameters associated with the JAGXTREME terminal are underlined in
the above formulas. The other parameters are related to the other approved apparatus
or the connecting cable.
If the above conditions are not true, then the circuit must be treated as an incendive
input or output and protected accordingly. If the parameters compare favorably as
shown above, then no special protection is required for the wiring. Always refer to the
electrical regulations for the country of installation for specific wiring requirements.
The following inputs and outputs are rated non-incendive on the JAGXTREME terminal
by either Factory Mutual or KEMA. The field circuit parameters for each I/O are also
listed.
Analog Load Cell (5v excitation only)
Factory Mutual
V = 5.5 VDC
t
I = 219 mA
t
C = 600 µF
a
= 705 µH
L
a
or U (Total voltage output)
t o
or I (Total current output)
t o
(Cable capacitance) ≤ C
a
(Cable inductance) ≤ L
or L
a
KEMA
U = 5.2 VDC
o
I = 222 mA
o
C = 200 nF
o
= 300 µH
L
a
P = 1.1 W
o
or C (Allowable capacitance)
o
(Allowable inductance)
o