L91 – 48 x 48mm Safety Limit Controller

Name: L91
SKU: L91
Availability: InStock

Microprocessor Based Limit Controller.

L91 Features:

4-digit LED display with status icons
Lockout function for secure operation
1/16 DIN compact panel mounting
Sampling rate: 5 times per second
Output 2 supports alarm, RS-485, power, retransmit
Alarm annunciator and event input available
Modbus RTU protocol support via RS-485
18-bit A/D resolution for high precision
Output indicators (OP1, OP2), °C/°F display

Brand: BRAINCHILD
Usually in stock

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L91 Limit Controller
Compact Safety for Temperature Protection

Designed for industrial over-temperature monitoring and alarm safety

The L91 from BrainChild is a microprocessor-based limit controller engineered for precise over-temperature protection in industrial systems. With universal input compatibility (TC, RTD, voltage, current), latching relay output, and dual display interface, the L91 ensures fast and reliable safety responses. Its output flexibility includes relay, SSR, or TRIAC, while Output 2 supports expansion to alarms, Modbus communication, or analogue retransmission.

Real-Time Display with Function Keys

Monitor PV, outputs, alarms, and status at once

The L91 panel adopts a compact yet efficient layout, featuring a high-visibility 4-digit red LED display to present real-time process values. The four-key interface includes Scroll, Up, Down, and Reset (R) buttons, allowing users to navigate menus, adjust parameters, and reset alarms efficiently. The Reset key also supports unlock/confirm actions via long press. The panel further includes a LOCK status LED, which secures access against unauthorized configuration changes.

Universal Input Compatibility for Accurate Monitoring

Supports TC, RTD, Voltage, Current, and mV Signals

The L91 is equipped with a high-precision 18-bit A/D converter and supports a wide variety of input signals including thermocouples (J, K, T, E, B, R, S, N, L), RTDs (PT100 DIN and JIS), low voltage (mV), standard voltage (0–1V, 0–10V), and current (0–20mA). With a sampling rate of 5 times per second (200ms), it ensures rapid response and stable measurement. Additional protections such as sensor break detection and programmable digital filtering enhance system reliability and measurement stability.

Power

90 – 250 VAC, 47 – 63 Hz, 10VA, 5W maximum

11 – 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
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
Burn-out Current	200nA
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%	2.2M?
mA	-3mA -27mA	±0.05%	70.5Ω
V	-1.3V-11.5V	±0.05%	302KΩ

Event Input
Logic Low	Logic -10V minimum, 0.8V maximum.
Logic High	2V minimum, 10V maximum.
Functions	Remote reset, remote lockout.

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

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

DC Voltage Supply Characteristics ( Installed at Output 2 )
Type	Tolerance	Max. Output Current	Ripple Voltage	Isolation Barrier
20V	±1 V	25 mA	0.2 Vp-p	500 VAC
12V	±0.6 V	40 mA	0.1 Vp-p	500 VAC
5V	±0.25 V	80 mA	0.05 Vp-p	500 VAC

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	8 bits
Parity Bit	None, Even or Odd
Stop Bit	1 or 2 bits
Communication Buffer	50 bytes

User Interface
4-digit LED Displays	0.4″ (10mm),
Keypad	4 keys
Programming Port	For automatic setup, calibration and testing
Communication Port	Connection to PC for supervisory control

Limit Control
High Limit, Low Limit and High/Low Limit programmable

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	0 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 C91 —48mm(W) X 48mm(H) X 94mm(D), 86 mm depth behind panel
Weight	C21 — 120 grams C91 — 140 grams

Approval Standards
Safety	FM Class 3545 (Oct. 1998), UL873 ( 11’th edition, 1994 ) , CSA C22.2 No. 24-93 , EN61010-1 (IEC1010-1)
Protective Class	IP30 front panel, indoor use, IP20 housing and terminals ( with protective cover)
EMC	EN61326

L91-(1)-(2)-(3)-(4)
Type	Code	Specification
(1) Power Input	4	90 – 264 VAC, 47-63 HZ
(1) Power Input	5	11 – 26 VAC or VDC, SELV, Limited Energy
(2) Signal Input		1	Standard Input *
		2	Voltage 0-1 V
		3	Voltage 0-10 V
		4	Current 0-20 mA
		9	Special Order
(3) Output 1			0	None
			1	Relay rated 2A / 240VAC
			2	Pulsed voltage to drive SSR, 5V / 30mA
			6	Triac output 1A / 240VAC,SSR
			c	Pulsed voltage to drive SSR, 14V/40mA
			9	Special order
(4) Output 2				0	None
				1	Form A relay 2A / 240VAC
				2	Pulsed voltage to drive SSR, 5V / 30mA
				6	Triac output, 1A / 240VAC, SSR
				7	Isolated 20V/25mA DC Output Power Supply
				8	Isolated 12V/40mA DC Output Power Supply
				9	Isolated 5V/80mA DC Output Power Supply
				A	RS-485
				B	Event input
				C	Pulsed voltage to drive SSR, 14V/40mA
				D	Retransmit 4-20mA / 0-20mA
				E	Retransmit 1-5V / 0-5V
				F	Retransmit 0-10V
				H	Special orde
* Covers Inputs for Thermocouple J,K,T,E,B,R,S,N,L,C,P RTD: PT100 DIN,PT100 JIS & mV 0-60mV

Brainchild L91 Limit Controller - User Manual 1.67 MB

Product Range

Product Range:
Code	Specifications	Price
L91-411B	Safety Limit Controller, Standard input, Relay, 90~264Vac, Event Input option	$276.00
L91-4111	Safety Limit Controller, Standard input, Dual Relay, 90~264Vac	$276.00
L91-5111	Safety Limit Controller, 48 x 48mm, Standard input, Dual Relay, 11~26Vac/dc	$298.00

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

Intech Instruments Ltd are New Zealand distributors for Brainchild products. Please contact the Brainchild distributor in your country if you require sales or service support for Brainchild products.

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L91 Features:

Brand: BRAINCHILD
Usually in stock

L91 Limit Controller
Compact Safety for Temperature Protection

Designed for industrial over-temperature monitoring and alarm safety

Real-Time Display with Function Keys

Monitor PV, outputs, alarms, and status at once

Universal Input Compatibility for Accurate Monitoring

Supports TC, RTD, Voltage, Current, and mV Signals

Product Range

Who we are

Intech Christchurch

Intech Auckland

Newsletter

L91 – 48 x 48mm Safety Limit Controller

L91 Features:

Brand: BRAINCHILD Usually in stock

L91 Limit Controller Compact Safety for Temperature Protection

Designed for industrial over-temperature monitoring and alarm safety

Real-Time Display with Function Keys

Monitor PV, outputs, alarms, and status at once

Universal Input Compatibility for Accurate Monitoring

Supports TC, RTD, Voltage, Current, and mV Signals

Product Range

Footer

Who we are

Intech Christchurch

Intech Auckland

Newsletter

Brand: BRAINCHILD
Usually in stock

L91 Limit Controller
Compact Safety for Temperature Protection