gefran GT 25 Manual

Main applications
• Plastics extrusion lines
and injection moulding
machines
• Polymerization plant for
synthetic fibre production
• Rubber moulding
machinery
• Driers for ceramics and
components for the
building industries
• Chemical and
pharmaceutical industries
• Industrial electric furnaces
• Food processing plants
PROFILE
The GT family of solid-state relays has
been designed with the aim of providing
very accurate control of the load thanks
to an analog control input, in voltage at
0...5V; 0...10V or in current at
0...20/4...20mA or a potentiometer (from
1KΩ to 10 KΩ).
The electronic design ensures that the
cycle time for proportioning the power is
automatically optimized.
Il numero di periodi che il GT fornisce al
carico ("treni d' onda") per un certo
valore di segnale di ingresso, è calcolato
in modo da essere il minimo possibile,
pur mantenendo la precisione
necessaria.
The number of cycles that the GT
supplies to the load (wave trains) for a
given input signal is calculated to be the
minimum possible to maintain the
necessary accuracy.
The GT can be used in three phase
systems, using master-slave control
architecture in which the control signal
drives only one GT (master) and this unit
supplies the synchronized signals to the
other slaves. Two GS modules can also
be used as slaves (logic control).
A load interrupt control option (HB) is
available without having to use an
external current transformer; alarm limit
GT 25 / 40 / 50 / 60 / 75 / 90 / 120A
SOLID STATE RELAYS WITH ANALOG CONTROL
is settable with trimmer and yellow LED
signal, with voltage-free contact, normally
open.
The GT solid-state relay has a green
LED to indicate the presence of the
24Vac power supply and a red LED to
indicate the switching based on the
analog control input signal.
The LED signal will be continuous (off at
minimum, on at maximum) at the ends of
the scale, pulsing for intermediate
values.
The units offer optional accessoires for
panel mounting, fuses and fuseholders,
current transformer, isolation
transformers.
Use the relè with an opportune heatsink
(see section accessories).
Main features
• Command input from analogue voltage
or current signal or potentiometer.
• Switching at voltage zero crossing.
• Partialization of wave train power with
dynamically optimized time cycle.
• Antiparallel double SCR
• 2 led for supply indication, "ON" state,
1 optional LED for load interrupt alarm
• 4000V isolation between input circuit
and power output
• MOV (varistor)
• Optional monitoring of interrupted load
TECHNICAL DATA
General features
Category of use AC1
Nominal voltage
- 480Vac (max. range 24...530Vac)
Nominal frequency: 50/60Hz
Non-repetitive voltage: 1200Vp
Zero switching voltage: ≤ 20V
Voltage drop at nominal current ≤ 1.4Vrms
Power factor = 1
Control inputs
Voltage: 0...5Vdc, 0...10Vdc
(impedance ≥100KΩ)
Current: 0...20mA, 4...20mA
(impedance 125Ω)
Potentiometer: da1K a 10KΩ
(auto-fed by GT)
O
UTPUTS
GT 25 (SCR version)
Nominal currents of the device with
opportune heatsink in continuous work:
25A
Non-repetitive overcurrent t=20 ms: 400A
t for blowout: ≤ 645A
I 2 2 s
dV/dt critical with output deactivated:
1000V/µs
GT 40 (SCR version)
Nominal currents of the device with
opportune heatsink in continuous work:
40A