Designed to initiate an alarm relay contact closure when the
4-20mA loop current goes above or below a given value.
Operating power derived from the input current loop.
Fail Safe S.P.D.T. Form C, 2 amp max dry contacts.
Multi-turn alarm set-point adjustment calibrated by setting
millivolt value to correspond to desired alarm trip point.
Alarm may be configured to trip on increasing or decreasing
signals via DIP switch.
Latching or auto-reset action set by DIP switch.
3 values of deadband available via DIP switch.
Contributes less than 7.5 volts of additional loop voltage
drop.
L.E.D. visual alarm condition indicator.
High density DIN rail mount enclosure is less than 1 inch
wide. Also available in NEMA 4X and NEMA 7.
Model GDS-55 Loop Powered Alarm is designed to initiate
actions, such as turn on a horn or shut down a motor, when
the loop 4-20mA signal goes below or above a certain value.
It may be installed in any 4-20mA process loop where a fail
safe, completely isolated, S.P.D.T. dry contact relay output
is needed for switching AC or DC loads. The GDS-55 derives
all operating power from the current loop and has a voltage
drop of 7.5 volts.
Three values of deadband for the automatic reset mode may
be selected by the positioning of internal DIP switches. Manual
reset (latching mode) may also be selected via the internal
DIP switch. In this mode of operation it is necessary to press
the local pushbutton in order to clear an alarm condition.
The alarm set-point is fully adjustable from 0-100% of full
scale. There is no need to simulate the trip point at the
4-20mA input to calibrate the set-point. Simply measure the
set-point millivolt signal at the terminals provided and adjust
the 25 turn trimpot until the proportional desired value is
reached.
Since all operating power is derived from the current loop,
no power supply wiring exists. This makes the Model GDS-55
a very easy device to install. However, it must be remembered
that 7.5 volts of the loops' original drive potential is sacraficed
by addition of an GDS-55. The GDS-55 input impedance adds
approximately 375 ohms to the loop when the input current
is 20mA.
Designed to eliminate problems often encountered when terminating
current loops
Provides continuous 1500 volt CMV isolation between input
and output current loops
Provides an isolated current analog output capable of driving
20mA through a 750 W load
Derives all operating power from the input current loop
Contributes less than 1.75 volts of additional loop voltage
drop
Requires no calibration
High density DIN rail mount enclosure is less than 1 inch
wide.
Model GDS-51A Loop Powered Isolator is designed to eliminate
problems often encountered when terminating field current
loops to control room instrumentation. A chopper amplifier
and inductive coupling transformer provide complete electrical
isolation, eliminating ground loops and protecting control
room devices from noisy transients and high fault condition
voltages.
The Model GDS-51A accepts current loop inputs as low as 1
milliamp and duplicates them at the isolated current output.
No potentiometers exist within the unit and there is no complicated
calibration procedure to perform.
Since all operating power for the circuit is derived from
the current loop, no power supply wiring exists. This makes
the Model GDS-51A a very easy device to install. Also, very
little loop drive capability is sacrificed since the additional
loop voltage drop is less than 1.75 volts. The GDS-51A input
impedance adds less than 87 ohms to the loop when the input
current is 20mA. For example: If an GDS-51A output drove current
into a 250 ohm load; and if the field wiring impedance was
50 ohms, then the drive capability required by the current
transmitter would be no more than 387 ohms.
0711 Vortec Mini Cooler R1201612 Rack Assembly Free standing/Mounting rack
60350438 Zancha Associates, Inc. Maintenance Kit Kit comprised of most replacement parts that are common maintenance items.
If you are looking for tubing, fittings, pump heads, motors, etc...please contact us and we will be happy to send you a quotation for all your accessories/spare parts requirements.
CO2 Remover/ Air Dryer 
GDS-55 Loop-Powered Alarm 
GDS-51A Loop Isolator 
