Function; Supplementary Documentation - Endress+Hauser nivotester FTC 422 Montage- Und Betriebsanleitung

Introduction
Fig. 2
Summary of Nivotester FTC 422
front panel features
20

Function

The probe and container (or the ground-pipe of the probe) act as a
capacitor, the capacitance of which is dependent upon the level of
liquid or solids present. The electronic insert, usually mounted in
the probe head, passes a level-proportional voltage signal to the
Nivotester for evaluation. This actuates the output relay when the
preset level is exceeded or dropped below. The relay remains
de-energised until the second switch point is reached. The
resulting signal can be used to drive an annunciator, actuator or
further relay.
A wire bridge on the terminal block sets the output relay to act in
minimum or maximum fail-safe mode. The switching status of the
relay is indicated at the front panel by a red, the operational status
by a green LED. On power failure both LEDs extinguish - the
output relay de-energises.
Bridge12-13: Selection of
Max.- or Min.-Failsafe mode
Terminals 1, 2, 3:
Power supply, electrically
isolated from probe circuit

Supplementary documentation

Before proceeding with the installation of the Nivotester FTC unit,
check that the following documentation is at hand.
• Installation instructions for the capacitive probe to be used.
• Installation instructions for EC 61 Z electronic insert.
Nivotester FTC 422
Terminals 8, 9, 10:
Short-circuit protected
probe power circuit
Green LED:
Operational status
Red LED:
Relay status
Terminals 4, 5, 6:
Relay output