Brainchild Safety L91 Limit Controller

 The limit control L91 is over-temperature protection or a high limit safety device with a latching output, that removes power in an abnormal condition during the process is higher than the high limit set point or lower than the low limit set point.

The unit is powered by 11-26 or 90-264 VDC/VAC supply, incorporating a 3 amp. form C relay for limit control, an universal input which is fully programmable for PT100, thermocouple types J,
K, T, E, B, R, S, N, L and 0~60mV, an option port available for one of the following functions: alarm output, RS-485 communication interface, DC power supply output, limit annunciator output and event input. Alternative output options include SSR drive and triac. The input signal is digitized by using an 18-bit A to D converter. Its fast sampling rate (5 times/second) allows the L91 to control fast processes such as pressure and flow.

Digital communication RS-485 is available as an additional option. This option allows L91 to be integrated with a supervisory control system. An alarm output is another option. A variety of alarm function and alarm mode can be programmed for a specific application. The DC power supply output option is used for an external sensor or transmitter. The event input option can be programmed for remote reset or remote lock signal input. The limit annunciator option can be used to control an alarm buzzer.

Thress kinds of method can be used to program L91.

1. Use keys on front panel to program the unit manually,
2. Use a PC and setup software to program the unit via RS-485 port and
3. Use a pc and configuration software to program the unit via programming port.

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High accuracy, maximum flexibility, fast response and user-friendly are the main feature of L91

Specification

Power

90 - 250 VAC, 47 - 63 Hz, 10VA, 5W maximum
11 - 26 VAC / VDC, SELV, Limited Energy, 10VA, 5W maximum

Signal Input

Signal Input	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
Burn-out Current	200nA
Sensor Break Detection	Sensor open for TC, RTD and mV inputs, 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.

Accuracy

Characteristics
Type	Range	Accuracy@ 25 °C	Input Impedance
J	-120 ~ 1000 °C (-184 ~ 1832 °F)	±2 °C	2.2MΩ
K	-200 ~ 1370 °C (-328 ~ 2498°F)	±2 °C	2.2MΩ
T	-250 ~ 400°C (-418 ~ 752°F)	±2 °C	2.2MΩ
E	-100 ~ 900 °C (-148 ~ 1652 °F)	±2 °C	2.2MΩ
B	0 ~ 1800 °C (32 ~ 3272 °F)	±2 °C (200°C - 1800°C)	2.2MΩ
R	0 ~ 1767.8 °C (32 ~ 3214 °F)	±2 °C	2.2MΩ
S	0 ~ 1767.8 °C (32 ~ 3214 °F)	±2 °C	2.2MΩ
N	-250 ~ 1300 °C (-418 ~ 2372 °F)	±2 °C	2.2MΩ
L	-200 ~ 900 °C (-328 ~ 1652 °F)	±2 °C	2.2MΩ
PT100 (DIN)	-210 ~ 700 °C (-346 ~ 1292 °F)	±0.4°C	1.3KΩ
PT100 (JIS)	-200 ~ 600 °C (-328 ~ 1112 °F)	±0.4°C	1.3KΩ
mV	-8 ~ 70mV	±0.05%	2.2MΩ
mA	-3 ~ 27mA	±0.05%	70.5Ω
V	-1.3 ~ 11.5V	±0.05%	650KΩ

Input 2

Resolution	18 bits
Sampling Rate	1.66 times / second
Maximum Rating	-2 VDC minimum, 12 VDC maximum
Emperature Effect	±1.5uV/ °C for all inputs except mA input ±3.0uV/ °C for mA input
Common Mode Rejection Ratio ( CMRR )	120dB
Normal Mode Rejection Ratio ( NMRR )	55dB
Sensor Break Detection	Below 1 mA for 4-20 mA input, below 0.25V for 1 - 5V input, unavailable for other inputs.
Sensor Break Responding Time	0.5 second

Output

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

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

Interface

User Interface	Dual 4-digit LED Displays
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 )
Altitude	2000m maximum
Pollution	Degree 2
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	96mm(W) X 96mm(H) X 65mm(D), 53 mm depth behind panel
Mounting	48mm(W) X 48mm(H) X 94mm(D), 86 mm depth behind panel
Weight	150 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