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C21 PID Temperature Controller
C21 PID Temperature Controller
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C21 PID Temperature Controller
C21 PID Temperature Controller

C21 – 50x26mm Electronic Temperature Controller

Brand:

$289.00 Excl. GST

Select Power Input *

Signal Input *

Output 1 *

Output 2 *

Communications *

Display Colour

Total: $289.00

All prices are in NZ$, and GST exclusive and are subject to change without notice.

Product Details

C21 Temperature Controller | Compact PID Control

The BrainChild C21 Temperature Controller is a 1/32 DIN compact PID controller designed for precise thermal process management in space-limited industrial applications. Featuring auto-tuning fuzzy logic, it adapts dynamically to process changes while maintaining stable and accurate temperature control.

With a bright 4-digit LED display, fast 18-bit A/D conversion, and options for relay or SSR output, the C21 provides the ideal balance of performance and size. It also supports RS-232/485 communication and comes with multiple alarm configurations and soft-start ramping to ensure reliable, secure operation.

Panel Interface｜LED Display with 3-Key Control

The C21 temperature controller features a compact and efficient front panel interface built for simplicity and ease of use. At the center is a bright 4-digit red LED display, offering clear visibility of current process values and setpoints even in dim environments.

Below the display are three responsive silicone rubber keys designed for quick navigation, parameter setting, and control mode switching. The tactile feel ensures reliable feedback during setup or runtime adjustment, minimizing errors in industrial conditions.

The compact layout fits standard 1/32 DIN panel cut outs, making the C21 ideal for space-constrained equipment while maintaining full functionality and safety visibility.

Input Specs｜Universal Thermocouple & RTD

The C21 temperature controller accepts a wide range of universal input signals, including thermocouples (J, K, T, E, N, R, S) and RTDs (PT100 DIN/JIS). It also supports analogue signals such as 0–50 mV, 0–20 mA, 4–20 mA, with flexible scaling and cold junction compensation. A high-resolution 18-bit A/D converter ensures accurate process monitoring, while a fast 5 samples/second sampling rate provides responsive control for dynamic applications. The input circuit features built-in sensor break detection for added safety.

Output Options｜Relay, SSR & Analogue Ready

The C21 offers flexible output configurations to meet various control needs. Depending on model and settings, users can choose from:

  • Relay contact output: rated 2A/240VAC for on/off control
  • SSR drive voltage output: for external solid-state relay triggering
  • Analogue retransmission output: 0–20 mA, 4–20 mA, 0–10V with 15-bit D/A resolution

This output flexibility makes the C21 ideal for use in heating, cooling, or alarm control applications. Each output channel can be assigned to control, alarm, or retransmission functions based on system setup.

C21 Features

  • Bright 4-digit LED with easy-to-read display
  • High-accuracy 18-bit A/D input resolution
  • Supports thermocouples & RTD (PT100) input
  • High-accuracy 18-bit A/D input resolution
  • Fast 5 samples/sec A/D conversion rate
  • 2A relay or SSR voltage output selectable
  • Programmable ramping and dwell time
  • Auto/manual mode with bumpless transfer
  • Wide-range alarms: high, low, band, dwell
  • Lockout security with multiple access levels
  • RS-485/232 communication + PC setup port
  • CE, UL, CSA approvals with NEMA 4X / IP65 panel

Technical Specs

Power
90 – 250 VAC, 47 – 63 Hz, 10VA, 5W maximum
111 – 26 VAC / VDC, SELV, Limited Energy, 10VA, 5W maximum

 

Input 1 Characteristics
Resolution 18 bits
Sampling Rate 5 times / second
Maximum Rating -2 VDC minimum, 12 VDC maximum ( 1 minute for mA input )
Temperature Effect ±1.5 uV/ °C for all inputs except mA

input ±3.0 uV/ °C for mA input
Sensor Lead Resistance Effect T/C: 0.2uV/ohm

3-wire RTD: 2.6 °C/ohm of resistance difference of two leads

2-wire RTD: 2.6 °C/ohm of resistance sum of two leads 200nA
Common Mode Rejection Ratio ( CMRR ) 120dB
Normal Mode Rejection Ratio ( NMRR ) 55dB
Sensor Break Detection Sensor open for TC, RTD and mV inputs, Sensor short for RTD input, below 1 mA for 4-20 mA input, below 0.25V for 1 – 5 V input, unavailable for other inputs.
Sensor Break Responding Time Within 4 seconds for TC, RTD and mV inputs, 0.1 second for 4-20 mA and 1 – 5 V inputs.

 

TYPE Range Accuracy@25°C Input Impedance
J -120°C -1000°C (-184°F -1832°F) ±2°C 2.2MΩ
K -200°C -1370°C (-328°F -2498°F) ±2°C 2.2MΩ
T -250°C -400°C (-418°F -752°F) ±2°C 2.2MΩ
E -100°C -900°C (-148°F -1652°F) ±2°C 2.2MΩ
B 0°C -1820°C (32°F -3308°F) ±2°C (200°C – 1820°C) 2.2MΩ
R 0°C-1767.8°C (32°F -3214°F) ±2°C 2.2MΩ
S 0°C -1767.8°C (32°F -3214°F) ±2°C 2.2MΩ
N -250°C -1300°C (-418°F -2372°F) ±2°C 2.2MΩ
L -200°C -900°C (-328°F -1652°F) ±2°C 2.2MΩ
PT100 (DIN) -210°C -700°C (-346°F -1292°F) ±0.4°C 1.3KΩ
PT100 (JIS) -200°C -600°C (-328°F -1112°F) ±0.4°C 1.3KΩ
mV -8mV -70mV ±0.05% 2.2MΩ
mA -3mA -27mA ±0.05% 70.5Ω
V -1.3V-11.5V ±0.05% 302KΩ

 

Output 1 / Output 2
Relay Rating 2A/240 VAC, life cycles 200,000 for resistive load
Pulsed Voltage Source Voltage 5V, current limiting resistance 66

 

Linear Output Characteristics
Type Zero Tolerance Span Tolerance Load Capacity
4-20 mA 3.6-4 mA 20-21 mA 500Ω max.
0-20 mA 0 mA 20-21 mA 500Ω max.
0-5 V 0 V 5-5.25 V 10KΩ min.
1-5 V 0.9-1 V 5-5.25 V 10KΩ min.
0-10 V 0 V 10-10.5 V 10KΩ min.

 

Linear Output
Resolution 15 bits
Output Regulation 0.01 % for full load change
Output Settling Time 0.1 sec. ( stable to 99.9 % )
Isolation Breakdown Voltage 1000VAC
Temperature Effect ±0.0025 % of SPAN / °C

 

Triac ( SSR ) Output
Rating 1A / 240 VAC
Inrush Current 20A for 1 cycle
Min. Load Current 50 mA rms
Max. Off-state Leakage 3 mA rms
Max. On-state Voltage 1.5V rms
Insulation Resistance 1000 Mohms min. at 500 VDC
Dielectric Strength 2500 VAC for 1 minute

 

Alarm ( Output 2 )
Alarm Functions Dwell timer,
Deviation High / Low Alarm,
Deviation Band High / Low Alarm
Process High / Low Alarm
Alarm 1 Relay Form A,Max. rating 2A/240VAC, life cycles 200,000 for resistive load.
Alarm Mode Normal, Latching, Hold, Latching / Hold.
Dwell Timer 0.1 – 4553.6 minutes

 

Data Communication
Interface RS-232 ( 1 unit ), RS-485 ( up to 247 units )
Protocol Modbus Protocol RTU mode
Address 1 – 247
Baud Rate 0.3 ~ 38.4 Kbits/sec
Data Bits 7 or 8 bits
Parity Bit None, Even or Odd
Stop Bit 1 or 2 bits
Communication Buffer 50 bytes

 

Analog Retransmission
Output Signal 4-20 mA, 0-20 mA, 0-1V, 0-5V, 1-5V, 0-10V
Resolution 15 bits
Accuracy ±0.05 % of span ±0.0025 %/ °C
Load Resistance 0 – 500 ohms ( for current output ),10 K ohm minimum ( for voltage output )
Output Regulation 0.01 % for full load change

 

User Interface
Single 4-digit LED Displays 10mm
Keypad 3 keys
Programming Port For automatic setup, calibration and testing
Communication Port Connection to PC for supervisory control

 

Control Mode
Output 1 Reverse ( heating ) or direct ( cooling )action
Output 2 PID cooling control, cooling P band 50 ~ 300% of PB, dead band -36.0 ~ 36.0% of PB
ON-OFF 0.1 – 90.0 ( °F ) hysteresis control ( P band = 0 )
P or PD 0 – 100.0 % offset adjustment
PID Fuzzy logic modified , Proportional band 0 ~ 500.0 °C ,
Integral time 0 – 1000 seconds , Derivative time 0 – 360.0 seconds
Cycle Time 0.1 – 100.0 seconds
Manual Control Heat (MV1) and Cool (MV2)
Auto-tuning Cold start and warm start
Failure Mode Auto-transfer to manual mode while sensor break or A-D converter damage
Ramping Control 0 ~ 900.0°F/minute or 0 ~ 900.0 °F/hour ramp rate
Digital Filter Function : First order
Time Constant : 0, 0.2, 0.5, 1, 2, 5, 10, 20, 30, 60 seconds programmable

 

Environmental & Physical
Operating Temperature -10°C ~ 50°C
Storage Temperature -40°C ~ 60°C
Humidity 0 to 90 % RH ( non-condensing )
Insulation Resistance 20 Mohms min. ( at 500 VDC )
Dielectric Strength 2000 VAC, 50/60 Hz for 1 minute
Vibration Resistance 10 – 55 Hz, 10 m/s² for 2 hours
Shock Resistance 200 m/s2( 20 g )
Moldings Flame retardant polycarbonate
Dimensions C21 —50mm(W) X 26.5mm(H) X 110.5mm(D), 98.0 mm depth behind panel
Mounting C21 —panel mount, cutout 22 X 45( mm )
Weight C21 — 120 grams
Altitude 2000m maximum

 

Approval Standards
Safety UL 61010C-1 , CSA C22.2 No. 24-93 , EN61010-1 (IEC1010-1)
Protective Class NEMA 4X ( IP65 ) front panel for C21,
IP30 front panel for C91, all indoor use,
IP20 housing and terminals
EMC EN61326

Ordering Information

C-21-(1)-(2)-(3)-(4)-(5)-(6)
1 Power Input4: 90 - 250 VAC, 47-63 HZ
5: 11 - 26 VAC or VDC, SELV, Limited Energy
2 Signal Input1: Standard Input
Thermocouple: J, K, T, E, B, R, S, N, L
RTD: PT100 DIN, PT100 JIS 
2: 0 - 60 mV
3: 0 - 1 V
4: 0 - 5 V
5: 1 - 5 V
6: 4 - 20 mA
7: 0 - 20 mA
8: 0 - 10V
9: Special Order
3 Output 10: None
1: Relay rated 2A / 240VAC
2: Pulsed voltage to drive SSR, 5V / 30mA
3: Isolated 4 - 20mA / 0 - 20mA
4: Isolated 1 - 5V / 0 - 5V
5: Isolated 0 - 10V
6: Triac output 1A / 240VAC,SSR
C: Pulsed voltage to drive SSR, 14V/40mA
9: Special order
4 Output 20: None
1: Form A relay 2A / 240VAC
2: Pulsed voltage to drive SSR, 5V / 30mA
3: Isolated 4 - 20mA / 0 - 20mA
4: Isolated 1 - 5V / 0 - 5V
5: Isolated 0 - 10V
6: Triac output, 1A / 240VAC, SSR
7: Isolated 20V / 25mA transducer power supply
8: Isolated 12V / 40mA transducer power supply
9: Isolated 5V / 80mA transducer power supply
C: Pulsed voltage to drive SSR, 14V/40mA
B: Special order
5 Communications0: None
1: RS-485 interface
2: RS-232 interface
3: Retransmit 4 - 20 mA / 0 - 20 mA
4: Retransmit 1 - 5V / 0 - 5V
5: Retransmit 0 - 10V
9: Special order
6 Display Color0: Red color

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