Weidmuller G418 User Manual

Weidmuller Ltd.
10 Spy Court
Markham, ON L3R 5H6
Tel: [phone]
Fax: [phone]

Weidmuller Inc.
821 Southlake Blvd.
Richmond, VA 23236 U.S.A.
Tel: [phone]
Fax: [phone]

ISO 9001 Registered

Electronic Interface Modules

G418 Ultra SlimPak®

RTD Input, Field Configurable Isolator

• field configurable via DIP switches for different input­output combinations

• provides an isolated, linearised DC output

• output is linearized to temperature

• 3 port isolation to 1800Vdc between input, output and
power supply

• 5 field configurable output ranges 0-5V, 0-10V, 0-1mA
0-20mA, 4-20mA

• 9 to 30Vdc powered

• CSA approved, UL recognized, CE marked

Description

Application

Diagnostic LEDs

The Ultra SlimPak G418 is a DIN rail mount, RTD input signal conditioner with 1800Vdc isolation between
input, output and power. The field configurable input and output offers flexible, wide ranging capability
for Platinum and Copper RTDs.
The input of the G418 Ultra SlimPak can be configured for any one of up to sixteen temperature ranges (see
Tables 1 & 2). The output is linear to the RTD temperature input and can be set for either 0-5V, 0-10V,
0-1mA, 0-20mA or 4-20mA.
Wide ranging, precision zero and span pots allow 50% adjustablity of offset and span turn-down within
each of the sixteen switch selectable. ranges. For example, the 0-500°F range could be offset and turned
down to provide a 4-20mA signal representing 0-250°F (or 250-500°F).

The Ultra SlimPak G418 field configurable RTD input isolator is useful in eliminating ground loops and
interfacing RTD sensors to data acquisition and control systems. Three way isolation completely eliminates
ground loops from any source. Isolation protects expensive SCADA systems from ground faults and
significantly reduces the effect of high common mode voltages which are prevalent in many RTD
applications.
The constant current RTD excitation circuitry uses the third lead of the RTD to sense and compensate for
the RTD lead resistance, resulting in an accurate RTD temperature measurement.
High density DIN rail mounting offers an extremely compact solution for saving valuable panel space.

The G418 is equipped with a dual function LED signal monitor. The green, front mounted LED indicates
both DC power and input signal status. Active DC power is indicated by an illuminated LED. If the input
signal is more than 110% of the full scale range, the LED will flash at 1Hz. Below -10%, the flash rate is

0.5Hz. If the LED flashes very fast, then the RTD input wires are open circuit. An 8Hz flash indicates that
RTD input (+), terminal 41, is open circuit, or a 4Hz flash indicates that either RTD (-) or RTD Return, terminal
42 or 43, are open. The CAL LED is on under normal operating conditions. If the CAL LED is off when the
unit is powered, consult the factory for assistance.

Table 1:
G418 Platinum RTD temperature
range

Table 3:
Temperature input range switch
settings (SW2 - 1 through 5)

Table 4:
RTD input range switch settings
(SW2 - 6 through 8)

Table 2:
G418 Copper RTD temperature
ranges

Key: n ON