Overview
The base plate mounted isolated safety barrier PHD-11HF-28 transmits the input signals from switch contacts or proximity switches in the hazardous area to the safe area transistor outputs via the safety barrier isolation. Line fault detection is via a separate relay output (optional) and is indicated by an LED on the top of the module. Switches on the module are used to select the phase of the channel and whether the line fault detection function is required.
The product requires a separate power supply with triple isolation for power, input and output.
Line Fault Detection (LFD)
Line Fault Detection (LFD) is a user-selectable switch on the top of the module and is indicated by an LED. If a line fault is detected, the line fault relay is closed and the channel output relay is disconnected. Short circuit alarm (SC) for field input current >7mA; open circuit alarm (LB) for field input current <0.1mA; switch contact input; 22kΩ resistor must be connected in parallel at both ends of the switch for line fault detection (e.g., switch contact II in the wiring diagram).
Main technical parameters
| Number of channels: | two inputs and two outputs |
| Power supply: | |
| Power supply voltage: | 20~35V DC, power consumption of about 1W (24V DC, output 20mA) |
| Power protection: | power reverse protection |
| Hazardous side input: | |
| Input signal: | switch contact/proximity switch |
| Sensor supply voltage: | approx. 8V |
| Input/Output Characteristics: | |
| Field input current: | When ＞2.1mA, the output is closed, indicating ON; When ＜1.2mA, the output is open, indicating OFF. |
| Output e-c on/off state switching control: | DIP switches K1, K3 set to "ON" side, the transistor output e-c is on. DIP switch K1, K3 set to "OFF" side, transistor output e-c cutoff. DIP switch K2, K4 set to "ON" side, the circuit selects the indicator light red LFD alarm function. |
| Safety side output: | |
| Output signal: | transistor, alarm relay (optional) |
| Driving capacity: | output current ≤ 20mA (1.2kΩ), the maximum internal current of 100mA, a short-circuit current protection |
| Output characteristics: | NPN transistor emitter or open collector output |
| LED indicator: | green ⸺ power indication; yellow ⸺ output transistor normal working status; red ⸺ LFD indication, line failure alarm |
| Temperature parameters: | operating temperature -20℃~+60℃; storage temperature -40℃~+80℃ |
| Air relative humidity: | 10%~95%RH without condensation |
| Insulation strength: | intrinsically safe end and non-intrinsically safe end (≥3000V AC/min); between power supply and non-intrinsically safe (≥1500V AC/min) |
| Insulation resistance: | ≥100MΩ (input/output/power supply between) |
| Electromagnetic compatibility: | in line with IEC 61326-1 (GB/T 18268), IEC 61326-3-1 |
| Mean time to failure: | 100000 hours |
| Wire requirements: | cross-section ≥ 0.5mm2; insulation strength ≥ 500V |
| Applicable field devices: | dry contact or NAMUR type proximity switch inputs according to DIN19234, etc. |
| Installation site: | installed in the safe zone, can be connected with the highest in Zone 0, IIC, Zone 20, IIIC hazardous locations of the intrinsically safe instrumentation |
| Safety certification | |
| Certification body: | National Explosion-proof Electrical Product Quality Supervision and Testing Center CQST |
| Certification standard: | GB/T 3836.1-2021, GB/T 3836.4-2021 |
| Explosion-proof symbol: | [Exia Ga]ⅡC, [Exia Da]ⅢC |
| Certified parameters (between terminals 1-2): | Um: 250V AC/DC, Uo=10.5V DC, Io=15mA, Po=39.4W, Co=1.7μF, Lo=165mH. |
Use of the environment
1. The surrounding environment shall not have strong vibration, shock and large currents and sparks and other electromagnetic induction effects, the air should not contain chromium, nickel, silver plating corrosive media, should not contain flammable, explosive substances.
2. Relative humidity: 10%～95%RH without condensation.
3. Operating temperature: -20℃～+60℃; Storage temperature: -40℃~+80℃.
4. Altitude：≤3500m
Overall dimension
Wiring diagram
Terminal definition
| Terminals | Terminal function definition | |
| 13 | Power supply- | 20～35V DC |
| 14 | Power supply+ | |
| 1 | Input 1- | |
| 2 | Input 1+ | |
| 4 | Input 2- | |
| 5 | Input 2+ | |
| 7 | Transistor output 1 | |
| 8 | Transistor output COM | |
| 9 | Transistor output 2 | |
| 10 | Alarm relay output (optional) | |
| 11 | Alarm relay output (optional) | |
Wiring
1. Meter wiring adopts removable spring-type terminals, easy to use. The upper end of the instrument is intrinsically safe (blue plug), which leads to the signal terminal of the hazardous side; the lower end of the instrument is non-intrinsically safe, which is directly plugged into the base plate, and is supplied with power uniformly through the sockets and wiring on the base plate and leads to the signal terminal of the safe side;
2. Intrinsically safe side of the wiring should be selected with blue marking intrinsically safe wire, wire soft copper cross-sectional area must be greater than 0.5mm², insulation strength should be greater than 500V;
3. Isolated safety fence intrinsically safe side and non-intrinsically safe side of the wiring conductor in the sink should be laid separately, each using a protective sleeve;
4. The bare length of the wire is about 10mm, if the soft line also need to install metal size >10mm cold pressure head, hard line is not required. The wire can be directly inserted into the wiring hole without a screwdriver.
Installation
"Isolated safety barriers should be installed in a safe place, and also comply with
GB3836.13-2013: ""Explosive atmospheres—Part 13: Equipment repair, overhaul and reclamation""，
GB/T3836.15-2017: ""Explosive atmospheres—Part 15: Electrical installations design ,selection and erection"", GBT3836.16-2017: ""Explosive atmospheres―Part 16: Electrical installations inspection and maintenance"", GB/T3836.18-2017: ""Explosive atmospheres—Part 18: Intrinsically safe electrical systems"", GB15577-2018: ""Safety regulations for dust explosion prevention and protection"",
and GB50257-2014: ""Code for construction and acceptance of electric equipment on fire and explosion hazard electrical equipment installation engineering""."
Isolated safety grille adopts the bottom plate mounting method. The operation steps are as follows:
Disassembly
1. Pull out the instrument from the socket of the base plate upwards as follows:
2. When separating the wires on the terminals, please insert a standard screwdriver into the groove of the orange operation position and push it inward, then pull the wires out of the wiring hole.
Maintenance
1. Before power-on commissioning, you must check again whether the model and explosion-proof grade of the isolated safety barrier is consistent with the design and use of the environment, whether the wiring between the safety side and the hazardous side is correct, and whether the polarity of the power supply and signal is correct;
2. Strictly forbidden to use megohmmeter to test the insulation between the terminals of the isolated safety barrier. If you want to check the insulation of the system line, you should first disconnect all the isolated safety barrier wiring, otherwise it will cause the internal fast fuse blown;
3. Products are strictly inspected and quality controlled before shipment, if you find use of abnormalities, please contact your nearest agent or call the technical support hotline;
4. Six years from the date of shipment, the product in the course of normal use of the quality problems arising from us free of charge to solve.
Intrinsically safe explosion-proof circuit system
Isolated safety barriers and field intrinsically safe instrumentation connected to form an intrinsically safe explosion-proof circuit (intrinsically safe circuit) system must be confirmed before use:
1. The explosion-proof grade of the field intrinsically safe instrument should be in line with the use of the environment, and it should be the instrument which has been certified by the state-authorized explosion-proof product certification body and has obtained the explosion-proof certificate of conformity.
2. Isolated safety barriers and on-site intrinsically safe instrumentation between the respective certification parameters are clear, and in line with GB/T 3836.15-2017, such as the requirements of the 12th 12.2.5.
3. If any of these parameters are unclear and need to constitute an intrinsically safe circuit system, they must be confirmed by a state-authorized explosion-proof product certification body.