Building Automation Knowledge Base

Issue SPP920 Datasheet, Technical Information and Installation Instructions Product Line Field Device Environment SPP920 Differential Pressure Switch Cause No information available for the SPP920. The Sensor catalogue says it is supported by Huba. Resolution Either click link www.hubacontrol.com and search for 630. or the Technical information can be downloaded here. Installation Instructions can be downloaded here. Mechanical connections are: P1 = High Pressure (discharge/flow), P2 = Low Pressure (suction/vacuum) All of the various pressure range options come with the following options: - EPDM diaphram material - Brass Case - Spec Cover PG9 - IP65 Rating - Bracket Type A

Issue SPU 1201 Universal Pressure Switch – Specification No. 131-1-201 SPU 1202 Universal Pressure Switch – Specification No. 131-1-202 Product Line Field Devices Environment Site requesting a Universal Pressure Switch Cause SPU1201 and SPU1202 obsolescence Original PDF specification sheet is available here: DS21602-0203.pdf. Resolution The SPU1201 and SPU1202 have been made obsolete per the supplier. The closest replacement options that we have are listed below: SPU1201 is a 0.2 – 4.0 Bar device. The replacement options are SPP920 Series SPU1202 is a 12 – 250 mBar device. The replacement options are SPP920 Series Refer to Product Announcement PA-00166 for the SPP920 series Differential Pressure Switches for neutral and slightly aggressive liquids and gases.

Issue What resources are available to get more information on the Modbus protocol? Product Line Andover Continuum,EcoStruxure Building Operation,Field Devices,Satchwell BAS & Sigma,Satchwell MicroNet,TAC IA Series,TAC INET,TAC Vista Environment Modbus ASCII/RTU Modbus TCP/IP Cause The Modbus protocol information is available on www.modbus.org Use the menu on the left and select Technical Resources. Select the Modbus Specifications. Resolution Found on www.modbus.org are the protocol specifications: Modbus ASCII/RTU Modbus TCP

Issue SE8000 Best Practices Product Line Field Devices, EcoStruxure Building Expert Environment SE8000 Cause Best Practices for commissioning SE8000 room controllers Resolution The following information has been contributed by a field engineer and their experience to assist others in commissioning the SE8000 device. It brings together or provides leads to various articles that can be found on the Download Center. SE8K Programming Tutorial v1.1

Issue What actuator can be used as a replacement for the MF-63123? MF-631x3 Series_F_24732_8.pdf (209 KB) MFC 8000_F_25124_4.pdf (260 KB) Product Line Field Devices Environment MF-63123 Cause Original actuator has failed, or requirement for a non US actuator. Resolution Using the installed valve details, the actuator can be selected from the Schneider Electric Valve and Actuator selection Tool.

Issue The specifications and setup details of the EH series humidity sensors. Product Line Andover Continuum, EcoStruxure Building Operation, Field Devices, TAC IA Series, TAC INET, TAC Vista Environment Humidity Sensor Cause The EH Series Room, Duct and Outside humidity sensors are a universal Relative Humidity transmitter that can be powered with either a +15 to 36 Vdc or 24 Vac supply voltage. The EH series sensors are designed with a field selectable 4-20 mA, 0-5 Vdc, or 0-10 Vdc output signal that is equivalent to 0 to 100% RH. The EH Series is used in building automation system, humidity chambers, and OEM applications and is compatible with Vista, Continuum, I/Net, I/A, and SmartStruxure systems. Resolution EH Series Humidity Sensors Click the below links to look at the documentation for these sensors including the dip switch settings. EH Series Humidity Sensor Data Sheet EH Series Humidity Sensor Installation and Operation Instructions Old EH Series Humidity Model For information on the older style of dip switches (models with two separate sets of dip switches), see the document below. Old EH Series Humidity Sensor Installation and Operation Instructions

Issue Temperature Sensor Resistance Charts Product Line Andover Continuum, EcoStruxure Building Operation, Field Devices, Satchwell MicroNet, Satchwell Sigma, TAC IA Series, TAC INET, TAC Vista Environment Temperature Sensors Cause Temperature (°C) to Resistance Charts (ohms). Upgrading the site BMS, but retaining the existing sensors and the sensor resistance values are not known. Resolution The resistance of a sensor at a specific temperature can be downloaded below, there are a number of tables collated from different sources for a number of Schneider Electric sensors and other BMS suppliers.   In EBO, the thermistor selection in the IO module or controller does not represent the thermistor bead type, an example is the Continuum Type I in EBO, but the bead is a Type 3,. For further information regarding this see the KB article  Thermistor type selection in EBO.   The document All Sensors covers the following:   Satchwell DxT sensors are replaced by STR600, STP660, STD600, STO600 type T with shunt, and use the Satchwell T range chart Drayton DC1000, DC1100 30K6A1 is now known as STR600D, STP600D, STO600D Andover 10K4A1 TAC Inc. Vista 1.8KA1 I/A series 10K3A1 with 11K shunt INET 10K2A1 (10k Dale) BALCO 1000 ohm RTD   Older Satchwell ranges: Satchwell DW1204, DW1305, DWS1202 Satchwell DO Satchwell DD/DR Other manufacturers included: Allerton 3K3A1 Ambiflex 2012, Honeywell Aquatrol, Jel/Thorn, Trend, York 10K3A1 Schlumberger (air) 5K3A1 Schlumberger (immersion) 100K6A1 Automatrix, York, Sibe 10K4A1 Honeywell 20K6A Landis & Gyr PT100A, PT1000A   Further information regarding INET, IA, the document Thermistor Types Tables (Veris Industries) is available.  The 1k Balco resistance chart is also available.   Further information for the Continuum ACC Temp 10K Type 3 also known as 10K4A1, the document Thermistor Temp Resist Chart (Precon Thermistors) is available.   TC900 series TC900 RS-03 sensor chart   For I/A Series Controllers (MNL/MNB) Compatible sensors that have a built-in 11k shunt resistor include the TS-5711-850 TS-57011-850 TS-57031-850 TSMN-90110-850 Series Any sensor that matches resistance to temperature curve for a 10K Thermistor Type G (U.S. Sensor), Type 9 (Dale/Vishay) or Type III (ACI Series AH) can be used with the I/A Series MNL and I/A Series MNB series controllers, provided that a 11k ± 0.1% 1/8 watt resistor is wired in parallel with the sensor. The input has a range of -10 to 135 °F (-23.3 to 57.2 °C) with an accuracy of ±1% of span. Temperature / Resistance Reference Values Temperature Deg F (Deg C) Resistance Resistance Incl. 11k Shunt 32 (0) 25490 8,012 68 (20) 12,260 5,798 75 (25) 10,000 5,238 104 (40) 5,592 3,707 140 (60) 2,760 2,206 The full temperature/resistance table for the US Sensor 10K Thermistor R-T Curve Type G sensor. Please note that the controller may not be able to use the full temperature range shown in the table.  

Issue The SP90 Actuator alarm "BV:22 Temperature Sensors Missing or Interchanged" is triggered. Can we simply swap T1 and T2 in the configuration to fix this, instead of physically swapping the sensors? Product Line Field Devices Environment SpaceLogic SP90 Series Smart Actuator Cause The installer has installed the temperature sensors in the incorrect pipes. Resolution Firmware versions V439 (for actuators products marked V1xxx on the product label) and V539 (for actuators marked V2xx on the product label) introduced MSV:42 (T1 input) and MSV:43 (T2 input) which enable the temperature sensors to be swapped.   You are able to select each as: 1: Disabled 2: Supply temperature 3: Return temperature   If the SP90 actuator is at a lower firmware revision, it can be upgraded. Contact Product Support for the firmware files and upgrade instructions.

Issue In earlier SLP firmware the sensor displayed the CO2 with yellow and red as shown below:                               However new sensors display CO2 differently.   Is it possible to go back to the old look?   Product Line Field Devices Environment SLP Sensor Cause When launched, the SLA/SLP PM series sensor firmware was updated to display stoplight indicators (red, green, yellow) over the CO2 and PM values. In previous firmware, the stoplight function only applied to CO2 and the full screen showed red, green or yellow, but current firmware highlights the individual CO2 or PM value in the appropriate color. Resolution Firmware of this offer is not field upgradable; it is not possible to revert to the previous functionality.  

Issue Are stainless steel pockets suitable for use in seawater/saltwater applications? Product Line Field Devices. Environment STR Sensor. Cause Customer asking if stainless steel pockets are suitable for use in seawater/saltwater applications. Please note that the answer would need to cover both static (stationary) water and flowing water in the pipe, because seawater/saltwater has different effects on metals depending on whether it is moving or not. Resolution Highest corrosion class is Class III for stainless steel, which seems not suitable for intended application.   ISO 12944 Impact Interior Exterior C1 Very low Heated buildings with clean air, such as offices, shops, schools, hotels, etc. None C2 Low Buildings not heated, where condensation may occur, such as warehouses and sports halls. Atmosphere with low pollution. For example in the country. C3 Middle Buildings for production with high atmospheric humidity and some air pollution such as food manufacturers, breweries, dairies and laundries. Urban and industrial areas, moderate sulphur dioxide pollution. Coastal areas with low salt content. C4 High Chemical manufacturers, swimming baths and ship- and boatyards by the sea. Industrial areas and coastal areas with moderate salt impact. C5-I Very high - Industry Buildings or areas with almost permanent condensation and with high pollution. Industrial areas with high humidity and aggressive atmosphere. C5-M Very high Buildings or areas with almost permanent condensation and with high pollution. Industrial areas with high humidity and aggressive atmosphere.  

Issue What is the unit load of a TC900 thermostat and what are the bias and termination requirements when used with a SmartX Server. Product Line EcoStruxure Building Operation, Field Devices Environment TC907-3A4LMA TC907-3A4DLMSA TC907-4FMSA TC907-3A4DPMSA TC907-3A4DPMSA-24 TC903-3A4LMA TC903-3A4DLMSA TC903-4FMSA TC903-3A4DPMSA TC903-3A4DPMSA-24 SmartX Server Cause Documentation does not state the RS-485 transceiver type for the TC900 range, making it unclear how many devices can exist under a SmartX servers RS-485 serial port ComA or ComB. Resolution Use the Worksheet for Configuration of RS-485 Bus with generic RS-485 devices on Webhelp to determine the appropriate Modbus configuration. The answers to the transceiver interface attributes below can be applied to complete the worksheet. Q1 Failsafe Receiver : The TC900 uses an RS-485 transceiver with an integrated idle-state failsafe receiver. Q2 Data Transmission Speed : TC900 thermostats can be configured to communicate at 4800, 9600, 19200 or 38400 bps. Q4 Isolated Interface : The TC900 does not provide an isolated RS-485 interface. Q6a Measured Resistance : With no electrical connections to the TC900, the measured resistance between the RS-485 low-side (-) signal and the communications common is 8.2K ohms. Based on this the unit load of the TC900 is 1.46 (12.000/8,200) Bias requirements and number of devices If there are only TC900 devices on the RS-485 bus then Generic RS-485 Network Device configuration 1 applies, configuration becomes very simple and no node or distance reductions are called for. The failsafe receivers can typically operate with no added bias resistors. Connect a 120 ohm termination resistor across the + and - data lines at the head end of the bus (typically at the SmartX server). Connect another 120 ohm termination resistor across the + and - data lines on the last node at the far end of the bus. Connect the shield drain wire to earth ground terminal rail in the panel with the SmartX server. This is the only ground connection of the shield for the complete cable segment. Connect the RET/Shield terminal (see the figure below) on the SmartX server to the ground rail in the panel using a 12 AWG (3.31 mm²) to 18 AWG (0.82 mm²) wire. Since the TC900 has a unit load of 1.4 the maximum number of devices that can be placed under each comm port using this configuration is 21 (31.5 / 1.46 = 21.5) Also check out the SmartStruxure-RS485-Controller Unit Load Quick-Help video on the Exchange. Note:  Adding an RS-485 Repeater at this point provides another 32 Units Loads to the Network which can be continued up to the Architectural Maximum defined for the hosting controller.

Issue How to be redundant with your intelligent Building Management System (iBMS) Product Line Andover Continuum, EcoStruxure Building Operation, Field Devices, Satchwell Sigma, Security Expert, TAC INET Environment Existing intelligent Building Management System Open Mind High Availability Solutions (Deprecated by manufacturer) everRun MX ztC Edge Cause In engineering, redundancy is the duplication of critical components of a system with the intention of increasing the system's reliability. To be redundant with an intelligent Building Management System (iBMS) would take on two possibilities. Have an alarm on critical points alerting personnel who move into action quickly replacing control boards or devices in the event of failure. Have secondary backup controllers which upon failure, which are used to control devices resuming functionality. This is accomplished through programming the BAS with event sequences triggered from alarms or flags noting the failure. Redundancy capabilities and feasibility are site specific. Ascertaining failure in boards, points, or devices is crucial to creating secondary measures to keep seamless processes going and resume with functions.   Error detection and correction with maintenance is often the best practice for preventing failure. Worn components are the leading cause of failure, followed by a lack of planning and consideration in the protection of electrical components through power surges or failures.   For the database, backups including automated backups for MSDE, SQL Express, and Full SQL are available. For further information on database backups and options, take a look at Microsoft SQL Management Studio. For Host Computer backups, look at adding a secondary computer which replicates the database and can capture transactions and messages should a failure with the primary host computer take place. Also work with the local IT department to keep machines up to date, safe, and clean of 3rd party applications which may interfere with integrity. Schneider Electric’s building management systems are designed such that building control continues even when controller to server communication is disrupted. The BMS server is home to a database of alarm and historical data, as well as system parameters and programs. When a server or its network connection fails, the collection of data from building controllers halts until the problem is resolved. For data critical applications, this solution provides an environment capable of preventing the data loss that results from these types of failures.  Although we do support its use with EcoStruxure Building Operation, Security Expert, Continuum, I/NET, Vista, Sigma, and I/A Series as a disaster recovery solution, we do not provide direct support for EverRun. Resolution For Open Mind High Availability Solutions guide please look at the following link; Open Mind High Availability Solution guide For everRun MX solution guide please look at the following link; everRun MX guide For ztC Edge solution guide please look at the following link; ztC Edge guide   

   

Issue When a SED-TRH-G-5045 sensor is positioned outside the range of the main EBO Zigbee wireless mesh, what is the recommended method or product to extend the wireless coverage? Product Line EcoStruxure Building Operation Environment Building Operation Automation Server Premium Cause The SED-TRH-G-5045 is a Zigbee pro sleepy end device. Resolution Any Zigbee router within the system can function as a repeater to extend the radio communication. The router should be positioned within the radio range of the sensor and within the range of the RPx or another router. If a Zigbee device is powered by mains, it typically operates as a router. While there are currently no SE products designed solely with "repeater capability," several SE products possess router capabilities in addition to other capabilities, SE8000 SpaceLogic room controller Wiser plug CCTFR6500 Wiser Power Micromodule CCTFR6730 Wiser Room Thermostat with display CCTFR6400 or CCTFR6401. We have not officially tested any 3rd party Zigbee routers, however the IKEA TRÅDFRI repeater is known to work effectively.

Issue How to identify what ports are being used on a PC. Product Line All product Lines. Environment Any Windows OS Cause Running multiple applications on the same PC without managing TCP/UDP port assignments can lead to conflicts. Resolution TCPView will help you identify all ports and services to each application. Download from Microsoft's website http://technet.microsoft.com/en-us/sysinternals/bb897437.aspx Detailed instructions are available at the site.

Issue Does SHD2/SCD2 have galvanic isolation? Product Line EcoStruxure Building Operation Environment Building Operation SmartX Living Space Sensor Cause Galvanic isolation is a principle of isolating functional sections of electrical systems to prevent current flow; no direct conduction path is permitted. Resolution The SHD2XP2A/SCD2XPXAVX does not have galvanic isolation.

Issue SLP BACnet Setpoint limits Product Line EcoStruxure Building Operation, Andover Continuum, Field Devices Environment SpaceLogic SLP Series Cause The BACnet Object "Temperature Setpoint" includes properties Minimum and Maximum values These can be used to limit the setpoint, however the values are not saved in non volatile memory, thus the value revert to default after a power cycle (0 and 50 degC). The Setpoint object needs to be manually downloaded from EBO following a power cycle to set these properties. These properties cannot be written to individually. Thus changing these properties is unlikely to be good practice. Resolution A script program can be used to set limits to the Temperature Setpoint. Example below Note the "Value transfer settings" need changing to "Transfer value each time..." as below

Issue Information for replacement for the SPA1505 and SPA1506 Product Line Field devices Environment Pressure sensors Cause "PA-00167 Sensors and Input Devices New SPP930 Relative Pressure Switch" suggests SPP930 replaces SPA 1505 and SPA 1506. The link provided for the SPP930’s manufacturer’s data sheet, no longer works Resolution SPP930 Part number 004701160 replaces the SPA 1505 SPP930 Part number 004701170 replaces the SPA 1506 The site wiring should be checked, to ensure it complies with replacement switches reduced current ratings.   SPA 1505/1506 data sheet Huba Controls type 620/625 data sheet.

Issue The Insight Sensor and Multi Sensor Ambient Light Sensor require calibration before they can be effectively used. Product Line EcoStruxure Building Operation. Environment Insight Sensor. Multi Sensor Cause When setting up a new Insight Sensor or Multi Sensor device, the default settings for Gain and offset may result in inaccurate readings. Calibration is necessary to ensure accurate data collection based on the specific installation area. Resolution To perform the calibration, the following two tasks need to be carried out manually: Calibrate the Light Sensor: Conduct the calibration process in an environment without any daylight for optimal results. Set the light to 100%. Measure the lux level at the reference point using a lux meter. Adjust the gain settings on the sensor to match the measured lux level. Linearize the Feedback Signal: In some cases, lights may not provide a linear feedback (lux level) as the output increases. To compensate for this non-linearity, the signal from the controller is linearized before being sent to the output. During the optimization phase, the controller incrementally increases the output in 10% steps, measuring the adjacent lux levels for each step. The maximum lux supplement is calculated by subtracting the lux level at 100% output from the lux level at 0% output. After the optimization phase, breakpoints are determined and verified by re-running the test. If the results fall within the maximum difference limit compared to a linear signal, the calibration test is considered valid. Remember, performing the calibration process without any daylight present will yield the best results.  

Issue Satchwell AR Series 7 Rotary Actuator requires replacement Product Line Field Devices Environment Satchwell AR Series 7 Rotary Actuators installed on Air Dampers, Satchwell MB Series or MBF Series Rotary Shoe Valve Bodies. Actuator types :- ARE ARM ARX ARMS Cause Obsolescence of Satchwell AR Series 7 Rotary Actuators Resolution Replace Satchwell AR Series 7 Rotary Actuators with appropriate Schneider Electric MD Series Rotary Actuators and wire as follows :- Satchwell AR Series 7 Rotary Actuators installed on Air Dampers. ARE ARE Series 7 Wire Number 2 = MD20A-24 Wire Number 2 ARE Series 7 Wire Number 3 = MD20A-24 Wire Number 3 ARE Series 7 Wire Number 1 = MD20A-24 Wire Number 1 ARE Series 7 Wire Number 5 = MD20A-24 Wire Number 5 ARX ARX Series 7 Wire Number 3 = MD20B-24 Wire Number 3 ARX Series 7 Wire Number 2 = MD20B-24 Wire Number 2 ARX Series 7 Wire Number 1 = MD20B-24 Wire Number 1 ARM ARM Series 7 Wire Number 3 = MD20B-230 Wire Number 3 ARM Series 7 Wire Number 2 = MD20B-230 Wire Number 2 ARM Series 7 Wire Number 1 = MD20B-230 Wire Number 1 ARM Series 7 Wire EARTH = MD20B-230 NO EARTH REQUIRED ARMS ARMS Series 76021Term 3 (Open) = MD10SR-TS Blue G ARMS Series 7602 Term 2 (L1) = MD10SR-TS Not used *1 ARMS Series 7602 Term 1 (N) = MD10SR-TS Brown GO ARMS Series 7602 Wire EARTH = MD10SR-TS NO EARTH REQUIRED ARMS Series 7603 Wire Number 2 = MD10SR-T Blue G ARMS Series 7603 Wire Number 1 = MD10SR-T Brown GO ARMS Series 7604 Wire Number 2 = MD10SR-TS Blue G ARMS Series 7604 Wire Number 1 = MD10SR-TS Brown GO *1 Disconnect from the supply, label, and make safe at the supply and actuator.   N.B. Should the Satchwell AR Series 7 Actuator (not applicable to ARMS) include a wired Auxiliary Switch then the following Accessory should also be wired on the Schneider Electric MD Actuator as follows:- MD – S1 One independent SPDT 1 mA…3(0.5) A, 250 V AC Auxiliary Switch AR COMMON Wire Number S1 = MD-S1 COMMON Wire Number S1 AR N/O contact Wire Number S3 = MD-S1 N/O contact Wire Number S3 AR N/C contact Wire Number S2 = MD-S1 N/C contact Wire Number S2 MD – S2 Two independent SPDT 1 mA…3(0.5) A, 250 V AC Auxiliary Switches AR COMMON Wire Number S1 = MD-S2 COMMON Wire Number S1 AR N/O contact Wire Number S3 = MD-S2 N/O contact Wire Number S3 AR N/C contact Wire Number S2 = MD-S2 N/C contact Wire Number S2 AR COMMON Wire Number S4 = MD-S2 COMMON Wire Number S4 AR N/O contact Wire Number S6 = MD-S2 N/O contact Wire Number S6 AR N/C contact Wire Number S5 = MD-S2 N/C contact Wire Number S5   Satchwell AR Series 7 Rotary Actuators installed on Satchwell MB Series Screwed Rotary Shoe Valve Bodies. ARE ARE Series 7 Wire Number 2 = MD10A-24 Wire Number 2 ARE Series 7 Wire Number 3 = MD10A-24 Wire Number 3 ARE Series 7 Wire Number 1 = MD10A-24 Wire Number 1 ARE Series 7 Wire Number 5 = MD10A-24 Wire Number 5 ARX ARX Series 7 Wire Number 3 = MD10B-24 Wire Number 3 ARX Series 7 Wire Number 2 = MD10B-24 Wire Number 2 ARX Series 7 Wire Number 1 = MD10B-24 Wire Number 1 ARM ARM Series 7 Wire Number 3 = MD10B-230 Wire Number 3 ARM Series 7 Wire Number 2 = MD10B-230 Wire Number 2 ARM Series 7 Wire Number 1 = MD10B-230 Wire Number 1 ARM Series 7 Wire EARTH = MD10B-230 NO EARTH REQUIRED N.B. Should the Satchwell AR 7 Series Actuator include a wired Auxiliary Switch then the following Accessory should also be wired on the Schneider Electric MD Actuator as follows :- MD – S1 One independent SPDT 1 mA…3(0.5) A, 250 V AC Auxiliary Switch AR COMMON Wire Number S1 = MD-S1 COMMON Wire Number S1 AR N/O contact Wire Number S3 = MD-S1 N/O contact Wire Number S3 AR N/C contact Wire Number S2 = MD-S1 N/C contact Wire Number S2 MD – S2 Two independent SPDT 1 mA…3(0.5) A, 250 V AC Auxiliary Switches AR COMMON Wire Number S1 = MD-S2 COMMON Wire Number S1 AR N/O contact Wire Number S3 = MD-S2 N/O contact Wire Number S3 AR N/C contact Wire Number S2 = MD-S2 N/C contact Wire Number S2 AR COMMON Wire Number S4 = MD-S2 COMMON Wire Number S4 AR N/O contact Wire Number S6 = MD-S2 N/O contact Wire Number S6 AR N/C contact Wire Number S5 = MD-S2 N/C contact Wire Number S5   Satchwell AR Series 7 Rotary Actuators installed on Satchwell MBF Series Flanged Rotary Shoe Valve Bodies ARE ARE Series 7 Wire Number 2 = MD20A-24 Wire Number 2 ARE Series 7 Wire Number 3 = MD20A-24 Wire Number 3 ARE Series 7 Wire Number 1 = MD20A-24 Wire Number 1 ARE Series 7 Wire Number 5 = MD20A-24 Wire Number 5 ARX ARX Series 7 Wire Number 3 = MD20B-24 Wire Number 3 ARX Series 7 Wire Number 2 = MD20B-24 Wire Number 2 ARX Series 7 Wire Number 1 = MD20B-24 Wire Number 1 ARM ARM Series 7 Wire Number 3 = MD20B-230 Wire Number 3 ARM Series 7 Wire Number 2 = MD20B-230 Wire Number 2 ARM Series 7 Wire Number 1 = MD20B-230 Wire Number 1 ARM Series 7 Wire EARTH = MD20B-230 NO EARTH REQUIRED N.B. Should the Satchwell AR Series 7 Actuator include a wired Auxiliary Switch then the following Accessory should also be wired on the Schneider Electric MD Actuator as follows :- MD – S1 One independent SPDT 1 mA…3(0.5) A, 250 V AC Auxiliary Switch AR COMMON Wire Number S1 = MD-S1 COMMON Wire Number S1 AR N/O contact Wire Number S3 = MD-S1 N/O contact Wire Number S3 AR N/C contact Wire Number S2 = MD-S1 N/C contact Wire Number S2 MD – S2 Two independent SPDT 1 mA…3(0.5) A, 250 V AC Auxiliary Switches AR COMMON Wire Number S1 = MD-S2 COMMON Wire Number S1 AR N/O contact Wire Number S3 = MD-S2 N/O contact Wire Number S3 AR N/C contact Wire Number S2 = MD-S2 N/C contact Wire Number S2 AR COMMON Wire Number S4 = MD-S2 COMMON Wire Number S4 AR N/O contact Wire Number S6 = MD-S2 N/O contact Wire Number S6 AR N/C contact Wire Number S5 = MD-S2 N/C contact Wire Number S5   Product Information. For details of AR Series 7 ARM ARX ARE please see here For details of AR Series 7602 and 7603 please see here. For details of the MD10 SR Damper Actuator please see here. For details of MD10A please see here For details of MD10B please see here For details of MD20A please see here For details of MD20B please see here For details of MD-S1 please see here For details of MD-S2 please see here