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DC2948 Differential Controller

DC2948 Download PDF

Description

SYSTEM 2000 is totally Australian designed and manufactured. Exclusive circuitry gives the DC2948 Differential Controller all the features that has made this system an industry leader. The DC2948 Differential Controller is part of the System 2000 control range. It is a controller that accepts two resistive sensor inputs and switches a relay output, depending upon the temperature difference between them. The DC2948 can be fitted with up to four relay stages.

Technical Data

Supply Voltage 240v ± 10%
  24v ± 10%
Power Consumption 2VA
Ambient Temperature  
Operational 0 to 50°C
Storage Storage -20 to 60°C
Ambient Humidity Ambient Humidity max 90% RH
Enclosed Flame retardant ABS
Weight max 0.2kg
Size H: 140mm
  W
: 48mm
  D: 170mm
Relay Outputs  
SPDT Contacts Voltage Free 250VAC 2.5A

Relay Cards

The DC2948 relay cards have identical features:
1. Easy plug in replacement with expansion to 4 outlets.
2. 240VAC 2.5 amp ratings with voltage-free contacts.
3. Selection for operation of each relay stage on the D/A or R/A voltage signal.
4. Selection of each stage to operate as ON/OFF or TIME PROPORTIONAL basis with DIP switching. Relays 3 & 4 can be isolated from the internal D/A and R/A signal rails and operated through terminals 11 & 12 by an external 0-10VDC signal. The diagram shows the DIP switch positions.

Input Card

The DC2948 can be used with many different sensing devices provided they are of the resistive type. Zero and span adjustment potentiometers allow for use with thermistors, platinum and nickel resistive detectors. With two sensors connected between terminals 1 & 3 and 2 & 3 and the sensor connected to terminals 1 & 3 reduces its resistance; then the output voltage from terminal 6 increases to 10VDC. To operate one or more relays, terminals 6 & 7 are bridged.

Panel or Rear Mounting

All DC2948 Controllers are suitable for panel or rear mounting. Available in a white custom-made enclosure, the DC2948 can be mounted through the front panel of a switchboard to take full advantage of the digital display. Wiring is easy. The DIN rail (spring loaded clip system) supports the minimum of interconnections with all signal and high voltages at opposite ends.

Front Panel

Relay Setpoints & LED Display
The operation of the relay stages in the system are indicated by their respective LED’s and controlled by the potentiometers on the front panel. The pull in volts is set by the left potentiometer and the differential by the right potentiometer. When the relay is energised the LED is illuminated. The zero volts drop out feature prevents any relay from locking on if the differential voltage is set higher than the pull in volts. The internal circuitry will drop out the relay at 100mV. (The settings on the differential are in volts not in percentage of pull in volts.)

Internal Layout

Terminal Connection Diagram

Model Numbering System

Din Mounting Rail

Panel Mount Terminal Block