Rosemount 3490 Series Universal Control Unit

Transcription

1 Quick Installation Guide Universal Control Unit Start 1. Introduction 2. Installation 3. Getting Started 4. Application Examples 5. Other Features 6. Product Certifications 7. Other Safety Information End IP-rated Wall Mount NEMA4X-rated Wall Mount Panel Mount

2 Quick Installation Guide 2007 Rosemount Inc. All rights reserved. All marks property of owner. Emerson Process Management, Rosemount Inc. The Americas Emerson Process Management 8200 Market Boulevard Chanhassen, MN USA Tel (U.S.) Tel (International) (952) Fax(952) Europe, Middle East & Africa Emerson Process Management Shared Services Ltd. Heath Place Bognor Regis West Sussex PO22 9SH England Tel (44) Fax (44) Asia Pacific Emerson Process Management Singapore Pte Ltd. 1 Pandan Crescent Singapore Tel Fax AP.RMT-Specialist@emersonprocess.com This installation guide provides basic guidelines for the Rosemount 3490 Series Universal Control Unit. It does not provide instructions for detailed configuration, diagnostics, maintenance, service, troubleshooting, or installations. Refer to the Reference Manual (document number ) for more instructions. The Reference Manual and Quick Installation Guide (QIG) are also available electronically on Electrical shock can result in death or serious injury Avoid contact with leads and terminals. High voltage, that may be present on leads, can cause electrical shock. Make sure the power to the is off, and the lines to any other external power source are disconnected or not powered while wiring the Control Unit Failure to follow safe installation and service guidelines could result in death or serious injury The Control Unit may be connected to a transmitter located in a hazardous area. The Control Unit must not itself be located in a hazardous area. Do not mount the Control Unit on a structure that is subject to vibration, or in a position where damage may be caused by impact, thermal stress or liquid ingress. The fuse must only be replaced with the type specified. If the equipment is likely to come into contact with aggressive substances, it is the responsibility of the user to take suitable precautions that prevent it from being adversely affected, thus ensuring that the type of protection is not compromised. Aggressive Substances - e.g. acidic liquids or gases that may attack metals or solvents that may affect polymeric materials. Suitable Precautions - e.g. regular checks as part of routine inspections or establishing from the material's data sheet that it is resistant to specific chemicals. Installation and servicing must be carried out by suitably trained personnel in accordance with the local code of practice. The equipment is not intended to be repaired by the user and is to be replaced by an equivalent certified unit. Repairs should only be carried out by the manufacturer or approved repairer. Use the equipment only as specified in this QIG and the Reference Manual. Failure to do so may impair the protection provided by the equipment. Do not connect a power supply exceeding 250 r.m.s. or dc, or apparatus containing a source exceeding 250 r.m.s. or dc Page 2

3 Quick Installation Guide INTRODUCTION This Quick Installation Guide (QIG) is for anyone who is installing / configuring a Control Unit with a Rosemount 3100 Series Ultrasonic Level Transmitter, and does not require detailed information. For detailed information, see Product Manuals (3100 Series) and (3490 Series). About the Control Unit Full support for Rosemount 3100 Series ultrasonic level transmitters. 4-line LCD display with back light - for text and graphics. 6-button keypad - for local interrogation and programming. Intuitive menu system. 4-20mA / HART input, and 2 digital inputs 5 relay outputs, and 4-20mA output. LED indicator for system health. Configuring is achieved from the front panel of the control unit. Figure 1. Front panel fascia 4-line back-lit LCD display Status LED Keypad Keypad The membrane keypad comprises 6 function buttons. They are used for navigating a hierarchical menu system and for configuring / viewing application parameters. Button What the button will do When the Full Primary Display is shown, press the red (ENTER) button to access the Hierarchical Menu System. At other times, this button is for selecting a menu option and for confirming an edited parameter value or option. When navigating the menu system, the UP-ARROW button is for moving upwards one line. At other times, this button is for scrolling up through a list of alphanumeric characters or a multiple-choice list of options. When navigating the menu system, the DOWN-ARROW button is for moving downwards one line. At other times, this button is for scrolling down through a list of alphanumeric characters or a multiple-choice list of options. The LEFT-ARROW button is for moving left e.g. to another character when editing a parameter value. The RIGHT-ARROW button is for moving right e.g. to another character when editing a parameter value. When navigating the menu system, the ESCAPE button will return you to the previous menu level. At other times, e.g. editing a parameter, it is for restoring a parameter value/option to the setting prior to when editing started. Status LED The LED is positioned below the LCD. It flashes once per second to indicate that the Control Unit and Transmitters are operating correctly. If there are operating difficulties (e.g. overheating) or a transmitter fault, the LED is constantly on. Page 3

4 Quick Installation Guide INSTALLATION Location for 3490 Series Control Unit The Control Unit must not be sited in a hazardous area. The wall-mount Control Unit is housed in a tough enclosure, IP65 or NEMA 4X rated depending on the actual model order code. If mounted outside, protect from direct heavy rain. The panel-mount version of the Control Unit is a standard DIN size, designed for direct mounting in a control panel. It is designed for panel mounting in a weatherproof environment. See also earlier safety warnings on page 2, and later product certification and safety information on page 15. Cabling for wall-mount IP65 Control Unit (Figure 2) 1. Undo 2 screws and lift cover away to reveal terminals. 2. Cable transmitter to the Control Unit through a cable gland. If you have model 3492, connect only Transmitter 1 now. Follow remaining steps, and then see Getting started with Model 3492 on page If mains powered unit, check voltage selector switch (230V or 115V); adjust if necessary. 4. Cable the power lead to the Control Unit through a cable gland. If mains powered, cable AC power supply to terminals 28 (Live) and 29 (Neutral) on the Control Unit. Note that mains Earth is not required. If DC powered, cable the 24 Vdc power supply to terminals 31 (-) and 32 (+) on the Control Unit. Do not apply power yet. 5. Connect terminal 30 (Intrinsically Safe Earth) to a High Integrity Earth if the transmitter is sited in a hazardous area. 6. Make connections to relay terminals and current output terminals, if required. 7. Seal unused cable entries with a blanking plug. 8. Replace and secure the terminal cover. Figure 2. Transmitter and Mains Power connections (wall-mount) (IP65 Control Unit) Page 4

5 Quick Installation Guide Cabling for wall-mount NEMA 4X Control Unit (Figure 2) 1. Mark and drill the enclosure to accept the cable glands or conduit to be used. Take care not to damage the circuit board during drilling. It is the responsibility of the user to ensure that the cable glands and connections are in accordance with local and national regulations. To maintain the NEMA 4X rating of the enclosure, type 4X connections must be used. 2. Open the enclosure door, undo 4 screws, and lift lower cover to reveal terminals. 3. Cable the transmitter to the Control Unit. If you have model 3492, connect only Transmitter 1 now. Follow remaining steps, and then see Getting started with Model 3492 on page If you have a mains powered unit, check the voltage selector switch (230V or 115V) and adjust if necessary. 5. Cable the power lead to the Control Unit. If mains powered, cable AC power supply to terminals 28 (Live) and 29 (Neutral) on the Control Unit. Note that mains Earth is not required. If DC powered, cable DC power supply to terminals 31 (-) and 32 (+) on the Control Unit. Do not apply power yet. 6. Connect the protective earth cables to the bonding points on the inside of the enclosure. Bonding between conduit entries must be part of the installation. 7. Make connections to relay terminals and current output terminals, if required. 8. Replace and secure the terminal cover. 9. Close the enclosure door. Cabling for panel-mount Control Unit (Figure 3) 1. Cable the transmitter to the Control Unit. If you have model 3492, connect only Transmitter 1 now. Follow remaining steps, and then see Getting started with Model 3492 on page If mains powered unit, check the voltage selector switch (230V or 115V) and adjust if necessary. 3. If mains powered unit, cable AC power supply to terminals 28 (Live) and 29 (Neutral) on the rear panel of the Control Unit. Note that mains Earth is not required. 4. If DC powered, cable the 24 Vdc power supply to terminals 31 (-) and 32 (+) on the Control Unit. 5. Do not apply power yet. 6. Connect terminal 30 (Intrinsically Safe Earth) to a High Integrity Earth if the transmitter is sited in a hazardous area. Figure 3. Transmitter and DC Power connections (panel mount) Page 5

6 Quick Installation Guide GETTING STARTED Getting started with Models 3491/ After completing the installation of both Control Unit and the transmitter, switch on the power. 2. The Control Unit will now search for a connected HART transmitter. 3. When the HART transmitter is found (~40 seconds), the Control Unit will read parameters from the transmitter and make them available in the menu system. 4. If the transmitter is being used for the first time, it will prompt for the Bottom Reference of the transmitter, and then automatically set-up the 4-20mA output span over this range. Edit the Bottom Reference with the arrow-buttons, and use the red (Enter) button to confirm the value. (The Bottom Reference can be changed later). 5. Once the start-up is completed, the Full Primary Display appears, showing the PV (Primary Value). After a period of keypad inactivity, the Full Primary Display automatically changes to show only the PV and Display Units but in a much larger character size to facilitate easier viewing - this is the Large PV Display. To restore the Full Primary Display, press any button. Figure 4. Typical Full Primary Display of model 3491 Off-line/on-line status. (Locked padlock = on-line) HART Transmitter communicating (Absent if idle) Relay (RL) status. (o = de-energized, = energized) See also Relays on page 14 Digital input status (o = de-energized, = energized) Bar graph of 4-20mA output Measured PV (Primary Value) Figure 5. Typical Full Primary Display of model 3493 Off-line/on-line status. (Locked padlock = on-line) HART Transmitter communicating (Absent if idle) Totalizer 2 Relay (RL) status. o = de-energized, = energized T = Totalizer See also Relays on page 14 Digital input status (o = de-energized, = energized) Totalizer 1 Measured PV (Primary Value) Page 6

7 Quick Installation Guide Getting started with Model 3492 NOTE: It is important to ensure that the two transmitters are connected to model 3492 in the correct manner and sequence. 1. After completing the installation of both Control Unit and the first transmitter only, switch on the power. The Control Unit will now search for a connected HART transmitter. When the transmitter is found (~40 seconds), it is automatically allocated a unique address of 1, and is designated "Tx1". Tx1 is automatically assigned to Input Channel 1 of the Control Unit. 2. After Tx1 is allocated, the Control Unit reads parameters from Tx1 and makes them available in its menu system. 3. If Tx1 is being used for the first time, there will be a prompt for the Bottom Reference of the transmitter. Edit the value with the arrow-buttons, and use the red (ENTER) button to confirm the value. 4. The Full Primary Display appears next (see Figure 6). 5. Turn off the power to the Control Unit, and connect the second HART transmitter. Route the transmitter cable through the gland next to the first transmitter s gland. Note that the transmitter can be connected to the same Control Unit terminals as the first transmitter. Alternatively, an optional external junction box can be used (customer supplied). 6. With both transmitters connected, turn on the power to the Control Unit. The Control Unit searches for the connected HART transmitters. After finding Tx1, the second transmitter is found (~40 seconds). The second transmitter is automatically allocated a unique address of 2, and is designated Tx2. Tx2 is automatically assigned to Input channel 2 of the Control Unit. 7. After Tx2 is allocated, the Control Unit reads parameters from Tx2 and makes them available in its menu system. 8. If Tx2 is being used for the first time, there will be a prompt for the Bottom Reference of the transmitter. Edit the value with the arrow-buttons, and use the red (ENTER) button to confirm value. 9. The Full Primary Display appears next (see Figure 6). The actual PV shown on the display remains that of Tx1, which is the factory default condition. You can change this to another value, usually the sum, difference or product of the two transmitter readings. After period of keypad inactivity, the Full Primary Display automatically changes to show only the PV and Display Units but in a much larger character size to facilitate easier viewing - this is the Large PV Display. To restore the Full Primary Display, press any button. Figure 6. Typical Full Primary Display of model 3492 Off-line/on-line status. (Locked padlock = on-line) Transmitter allocated Left vertical bar = Tx1 Right vertical bar = Tx2 Transmitter communicating (1=Tx1, 2=Tx2) Relay (RL) status. (o = de-energized, = energized) See also Relays on page 14 Digital input status (o = de-energized, = energized) Bar graph of 4-20mA output Measured PV (Primary Value) Page 7

8 Quick Installation Guide Quick tour of the Menu System (Figure 7 and Figure 8) 1. When Large PV Display is showing, press the red (ENTER) button to show the Full Primary Display. 2. When Full Primary Display is showing, press the red (ENTER) button to enter the MAIN MENU (top-level menu). 3. MAIN MENU sits above sub-level menus, which lead to further sub-level menus and parameter screens. 4. Navigation of the menu system is by using the arrow-buttons, the red (ENTER) button, and the ESC button. 5. Highlighted (blinking) text indicates which menu option is selected if the red (ENTER) button is pressed. 6. indicates further menu options available, accessible by using the DOWN-ARROW button. 7. indicates further menu options available, accessible by using the UP-ARROW button. 8. Programming of the Control Unit is best achieved through easy-to-follow Wizards. There is a collection of Wizards for most functions and applications. Wizards are all selected and started through the menu system. On page 9 and page 11 are simple application examples of using the Duty Wizard. 9. Additional features, such resetting to factory defaults, can found on page 13 onwards. Figure 7. How to enter and navigate the menu system Figure 8. MAIN MENU Overview Pressing the red (ENTER) button toggles the operating mode of the 3490 Series Control Unit. An open padlock indicates that the unit is off-line and parameter values can be changed. Selecting this will bring up the "Setup" menu for programming the 3490 Series Control Unit. Selecting this will bring up the "Setup" menu for optional HART transmitter (Tx1) programming. (Similarly for Tx2 on model 3492.) The transmitter Bottom Reference can be changed here. Selecting this will allow you to monitor live readings and diagnostic information for the 3490 Series Control Unit. Direct access menu for advanced users to select parameter screens using their 3 digit ID number. Selecting this will allow you to monitor live readings and diagnostic information from the HART transmitter, Tx1. (Similarly for Tx2 on model 3492.) Page 8

9 Quick Installation Guide APPLICATION/DUTY: LEVEL MEASUREMENT 1. With power on and the transmitter giving a HART signal to the Control Unit (see previous pages), you can now set-up the Control Unit for an application. This application example is for level measurement. Requirements Live level measurement in units of feet and over a range of 0 to 10 feet. High level alarm. Input Data Tank Shape: Linear (e.g. Square) Bottom Reference: 11 feet The transmitter is supplying the level measurements in units of feet. 2. Navigate the menu system to get to the "Duty Wizard" screen. (Keypad hints are alongside the screens.) 3. Start the "Duty" Wizard by pressing the red (ENTER) button once. 4. Work through the "Duty" Wizard prompts (Figure 9 on page 10) until completion; this occurs when the menu system re-appears. Keypad hints, for the illustrated Wizard sequence on the next page, are provided alongside the prompts. If applicable, adapt the example to suit your application. 5. Circled numbers in the illustrated Wizard sequence relate to these notes: (1) Select "Level" from the multiple-choice list. (2) Programme the 4-20mA output span with a level range (e.g. 0 to 10 feet) (3) Set-up a high level alarm - the relay RL1 is energized whenever the measured level exceeds a pre-set level and de-energizes below another pre-set level, as defined at these prompts. (4) Optional overrides to prevent individual relays from being energized for too little time or too much time. (5) Option to set-up further relays. 6. After exiting the Wizard, the level measurement will be live on the Primary Display. 7. Return to the main menu by holding the ESC key for a few seconds, releasing it when the MAIN MENU appears. 8. Go on-line by selecting the "Go on-line?" menu option, and then pressing the red (ENTER) button. Page 9

10 Quick Installation Guide Figure 9. Application Example: Level Measurement using Duty Wizard Page 10

11 Quick Installation Guide APPLICATION/DUTY: CONTENTS MEASUREMENT 1. With power on and the transmitter giving a HART signal to the Control Unit (see previous pages), you can now set-up the Control Unit for an application. This application example is for content (volume) measurement. Requirements Live contents measurement in units of litres. Low level alarm at 2000 litres. Input Data Tank Shape: horizontal cylinder with flat ends. Tank Diameter: 2.5 metres. Tank Length: 5 metres. The transmitter is supplying the level measurements in units of metres. 2. Navigate the menu system to get to the "Duty Wizard" screen. (Keypad hints are alongside the screens.) 3. Start the "Duty" Wizard by pressing the red (ENTER) button once. 4. Work through the "Duty" Wizard prompts (Figure 10 on page 12) until completion; this occurs when the menu system re-appears. Keypad hints, for the illustrated Wizard sequence on the next page, are provided alongside the prompts. If applicable, adapt the example to suit your application. 5. Circled numbers in the illustrated Wizard sequence relate to these notes: (1) Select "Contents" from the multiple-choice list. (2) The required tank shape is a pre-programmed shape from the library. (3) Maximum contents as calculated by Control Unit. It can be edited here if required. (4) Edit the 4-20mA output span with a content range (e.g. 0 to 24,543 litres). (5) Set-up low level alarm. Relay RL1 energizes when level is below 2000 litres; de-energizes above 2500 litres. (6) Option to set-up further relays. if required. 6. After exiting the Wizard, the contents (volume) measurement will be live on the Primary Display. 7. Return to the main menu by holding the ESC key for a few seconds, releasing it when the MAIN MENU appears. 8. Go on-line by selecting the "Go on-line" menu option, and then pressing the red (ENTER) button. Page 11

12 Quick Installation Guide Figure 10. Application Example: Contents Measurement using Duty Wizard Page 12

13 Quick Installation Guide OTHER FEATURES Restoring factory defaults (Erases all user-entered data) To reset Control Unit to factory defaults, navigate to "Load Defaults" screen and press the red (ENTER) button twice. PIN Security Personal Identification Number (PIN) security prevents unauthorized people from programming the Control Unit. Typically, this is set-up when all other programming has been completed. As with bank cards, there is one PIN number. The factory default is for PIN security to be inactive. To activate, navigate to the PIN screen and edit a 4-digit personal identification number (PIN) that you want. The PIN is edited with the arrow keys and confirmed with the ENTER key; the 4-digit PIN will then be replaced by " " to indicate that PIN security is active. (By default, PIN is a 0 if inactive). Once PIN security is activated, a prompt for the PIN will appear when needed for an activity, such as starting a Wizard. If correctly entered, no further PIN requests are made unless there is a period of keypad inactivity, or the "Cancel Password" option is selected from the MAIN MENU screen. This "Cancel Password" menu option appears only after correctly entering the PIN. The menu option disappears when selected, therefore making the Control Unit secure and prompt for the PIN when needed. Modes of operation An open padlock icon indicates the unit is presently in the off-line mode. In this mode, the unit can be programmed providing that you know the security PIN (if set-up). Additionally, the 4-20mA output and relays (except totalizer and sampler) are frozen. The fault relay de-energizes. A closed padlock icon indicates that the unit is presently in the on-line mode. In this mode, most of the unit cannot be programmed. However, if you attempt to programme, you are prompted to go off-line and then prompted to enter the security PIN (if set-up). Additionally, the 4-20mA output and all relays are not frozen. Page 13

14 Quick Installation Guide Relays Relay outputs 1 to 4 are normally On Point/Off Point relays which may be used to start/stop pumps or open/close valves at different levels. They normally energies at one level and de-energize at a different level. Alternatively, they may be programmed as out-of-limits alarms such that they are energized between defined points and will de-energies outside the defined limits. They may also be programmed to perform a variety of auto-sequences and auxiliary functions, such as pump-down operations, pump rotations to equalize wear, and desludge/cleaning. Relay output 5 is normally a fail safe fault relay but may be re-allocated to another duty. Relays can be set-up easily using the Relay Wizard, accessible by navigating to the RELAYS menu screen. Relay (RL) Status The relay status icons on the primary display have the following meanings: = energized (Relay is presently energized). 0 = de-energized (Relay is presently de-energized). A = Alarm (Relay energized due to active alarm). S = Sampler (Relay is allocated to sampling duty). T = Totalizing (Relay is allocated to totalizing duty). Comfort (System) Settings The SETTINGS menu allows changing of the time and date, changing the date format, switching off keyboard sound, changing language, and enabling PIN security. Page 14

15 Quick Installation Guide PRODUCT CERTIFICATIONS European Directive Information The EC declaration of conformity for all applicable European directives for this product can be found on the Rosemount website at A hard copy may be obtained by contacting your local sales office. ATEX Directive (94/9/EC) Complies with the ATEX Directive. Low Voltage Directive (2006/95/EC) EN61010 Part 1 : 2001 Pressure Equipment Directive (PED) (97/23/EC) 3490 Series Control Unit is outside the scope of PED Directive. Electro Magnetic Compatibility (EMC) Directive EN61326 (1997) amendments A1, A2, and A3 (Industrial locations, Class A) CE-mark Complies with applicable directives: EMC, ATEX, and LVD Restriction of Hazardous Substances (ROHS) 3490 Series Control Unit is exempt. Hazardous Locations Certifications ATEX Intrinsically Safe Approval I1 Certificate Numbers: SIRA 06ATEX7128 (Wall Mount), SIRA 06ATEX7129X (Panel Mount) Intrinsically Safe for II(1) G D, [EEx ia] IIC Ambient Temperature: -40 C to +55 C Technical data: a) Safety Parameters: Terminal 1 (24V) with respect to terminal 2 (Iin) Terminal 1 (24V) with respect to terminal 3 (Earth) Terminal 2 (Iin) with respect to terminal 3 (Earth) Ui = 0, Uo = 27.3 V, lo = 96.9 ma, Po = 0.66 W, Li = 0.22 mh, Ci = 0.6 nf b) The Capacitance and Inductance of the load connected must not exceed the following values: Special conditions for safe use (Certificate SIRA 06ATEX7129X): 1. Terminal 30 must be earthed in the safe area via a high integrity earth. Underwriters Laboratories Inc. (UL) Intrinsically Safe Approval I5 Project IDs: E308780, E Intrinsically Safe for Class I, Division 1, Groups A, B, C, and D Intrinsically Safe for Class 1, Zone 0, Group IIC Ambient Temperature: -40 C to +55 C Control Drawing: 71097/1210 Uo = V, lo = 96.9 ma, Po = 0.66 W, La = 2.26 mh, Ca = 70 nf Ui = 30 V, li = 120 ma, Li = 0.1 mh, Ci = 0.6 nf, Uo = 6.51 V (1) (Capacitive charging only), Io = 0, Po = 0 (1) Terminal 2 (Iin) with respect to terminal 3 (Earth) must be treated as a 6.51V source. The 6.51V is considered as being theoretical maximum to which a capacitive load across these terminals could become charged through leakage via internal series blocking diodes. This voltage does not contribute to the short circuit sparking risk of any external source connected to these terminals. Group Capacitance Inductance (mh) or L/R Ratio (μh/ohm) IIC μf (1) 1.2 mh 42 μh/ohm IIB 0.65 μf 10.9 mh 172 μh/ohm IIA 2.15 μf 21.9 mh 346 μh/ohm (1) μf of which total Ci of the hazardous area apparatus connected must not exceed μf. Page 15

16 Quick Installation Guide Canadian Standards Association (CSA) Intrinsically Safe Approvals I6 Project ID: Intrinsically Safe for Class I, Division 1, Groups A, B, C, and D Intrinsically Safe for Class 1, Zone 0, Group IIC [Ex ia] Ambient Temperature: -40 C to +55 C Control Drawing: 71097/1201 Uo = V, lo = 96.9 ma, Po = 0.66 W, La = 2.26 mh, Ca = 70 nf IECEx Intrinsically Safe Approval I7 Certificate Number: IECEx SIR X Intrinsically Safe for Zone 0, 20, [Ex ia] IIC, [Ex iad 20] Ambient Temperature: -40 C to +55 C Technical data: a) Safety Parameters: Terminal 1 (24V) with respect to terminal 2 (Iin) Terminal 1 (24V) with respect to terminal 3 (Earth) Terminal 2 (Iin) with respect to terminal 3 (Earth) Ui = 0, Uo = 27.3 V, lo = 96.9 ma, Po = 0.66 W, Li = 0.22 mh, Ci = 0.6 nf b) The Capacitance and Inductance of the load connected must not exceed the following values: Conditions of Certification (Panel Mount): 1. Terminal 30 must be earthed in the safe area via a high integrity earth. OTHER SAFETY INFORMATION Ui = 30 V, li = 120 ma, Li = 0.1 mh, Ci = 0.6 nf, Uo = 6.51 V (1) (Capacitive charging only), Io = 0, Po = 0 (1) Terminal 2 (Iin) with respect to terminal 3 (Earth) must be treated as a 6.51V source. The 6.51V is considered as being theoretical maximum to which a capacitive load across these terminals could become charged through leakage via internal series blocking diodes. This voltage does not contribute to the short circuit sparking risk of any external source connected to these terminals. Group Capacitance Inductance (mh) or L/R Ratio (μh/ohm) IIC μf (1) 1.2 mh 42 μh/ohm IIB 0.65 μf 10.9 mh 172 μh/ohm IIA 2.15 μf 21.9 mh 346 μh/ohm (1) μf of which total Ci of the hazardous area apparatus connected must not exceed μf. 1. Materials of construction: Model Code 349***P6*: Polycarbonate enclosure and cover. 304SS cover fixing screws. UV resistant Polycarbonate membrane keypad. Nylon cable glands and blanking plugs. Model Code 349***P4*: Polycarbonate enclosure and cover. Polyester & monel fastening. UV resistant Polycarbonate membrane keypad. Model Code 349***P7: Polyphenylene (PPO) enclosure and cover. Carbon Steel / Zinc plated fascia fixing screws. UV resistant Polycarbonate membrane keypad. Nylon and PBT terminal blocks with plated fittings. 2. Fuse on mains powered unit: 200mA (T) 5 x 20 mm 250V. 3. When connected to equipment located in a hazardous area, not meeting the requirements of clause (Isolation of circuits from earth or frame) in IEC :2006 (EN :2007), equipotential earthing must be ensured between the equipment and the intrinsically safe earth. An example of equipotential earthing is a cable with a cross sectional area greater than 4mm 2 and a resistance of less than 1ohm.