#terminal markings on contactors

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Standard Terminal Markings and Contact Designation on ship electrical system

Standard Terminal Markings and Contact Designation on ship electrical system

Contactor and relay terminal markings should conform to DIN EN 50005 standard. The markings make it possible to determine the terminals that are associated with the ship component, ie functions they are assigned to and standardize the markings for different manufacturers on ship electrical system. Terminal markings adjacent to main contacts have a single digit reference.Three-phase contactor…

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High/Low Temperature & Humidity Test Chamber Analysis in China Market

High/Low temperature & humidity test chamber is used to simulate a actual temperature and humidity environment which it may caused any influence for surrounding objects，due to electronic products widely application in various occasions, in order to design better product which meet relevant environmental standards, the temperature and humidity test has become an necessary test items, and high/low temperature and humidity test chamber widely used in many different industries such as aerospace product, electronic instrumentation, materials, electronic products and various electronic components, this environmental test chamber used to checking working performance of DUT in high temperature, low temperature or hot and humid environment. This article focuses on discussion environmental climatic chamber application on the LED lighting industry application. Lisun Electronics (Shanghai) Co., Ltd is one of best LED lighting test equipment supplier, our products involved photometric, colorimetric and electrical measurement, EMC & EMI test, electrical safety test and environmental test, our product line also included temperature & humidity test chamber. Our environmental climatic chamber is special design and manufacture based on many years experience and professional knowledge in the LED lighting industry, our products key technical index as following: 1、 Chamber Structure: 1) The chamber is produced by SUS304 Steel, the temperature keeping material is produced by Polyurethane hard foam and ultra-fine fiber glass, the doorframe heat insulated by Double high temperature aging silicone rubber door sealing strip. 2) Humidification system and circuit board system was designed separately which avoid leakage caused by humidification pipeline failure, and improve higher safety; the chamber built-in water purification device and automatic water protection. 3) With big glass window and inside built-in lighting luminaire to make easy observation, the left side of chamber has built-in φ50mm hole port, it can connect outside power supply cable or signal cable.

2、 Programmable PLC touch screen: 1) The temperature controller is used by Korean TEMI display in English/Chinese and German Siemens PLC(See below Figure 1), the temperature sensor is platinum PT100 Ohms/MV resistor.

                                          Figure 1

2) The TEMI display can be English or Chinese and show test curve, it come with maximum 120 sets of program 12000 segments 999 cycle step capacity, each segment test time can be set maximum 99 hours 59 minutes. 3) After set up test data and condition, the screen of display will be locked to avoid artificial touch and cause stop working, and it can communicate to PC via RS-232/RS-485 to monitor test process and implementation of automatic switching machine function. Besides, it combined automatic calculate function, the temperature and humidity conditions can be amended immediately to make sure temperature and humidity control more accurate and stable. 3、 Heating / Humidification Circulation System: 1) The compressor imported from France TECUMSEH brand(See below Figure 2) which can allow you get after sales support from many countries.

Figure 2

2) The heating system is full separately system which produced by Nickel chromium alloy electric heating type heater; the cold system is applied by fully enclosed fan cooled single-stage and cascade refrigeration mode. Application multi-wing blower strong air circulation design to avoid any dead ends, the test area can be evenly distributed temperature and humidity. Wind circulation cycle design, wind pressure, wind speed are meet test standards, the temperature and humidity stabilization time very quick after opened the door.

Compared with similar products in the market, our environmental climatic test chamber has following advantages: 1、 Many supplier claim theirs product’s inside working temperature can be reach to -20°C~+150°C or +150°C or -60°C~+150°C, but acoording to our acutal survey, the temperature range they marked was non-load temperature test condition, that means if DUT don’t working, then it can be reach this temperature but after EUT start working, the actualy temperature can’t reach they said. For example, when we put a 100w~150w tested luminaires inside of chamber, after light it up, the inside actual temperature only have -50°C(Setted test temperature is -60°C) or -30°C(Setted test temperature is -40°C). Lisun products can fully meet -20°C~+150°C or -40°C~+150°C or -60°C~+150°C test temperature range(Under tested lamp fully working status), this point can indicated that there have big difference between we used compressor, refrigerants and heating devices and our competitor used, our temperature climatic chamber used France TECUMSEH brand compressor and 6P capacity refrigerants. The below is GDJS-015A model testing pictures(See below Figure 3 and Figure 4):

Figure 3: 70°C test temperature and 70% test humidity (Tested luminaires full working status)

Figure 4: Set the lowest -20°C test temperature and PLC touch screen showing(Tested luminaire full working status)

2、 Our product adopted with Finland brand electronic humidity sensor, but as we know our competitor used dry ball device, the advantage of electronic humidity sensor is no need to do maintain work; but inside humidity sensor of dry ball not only have big accuracy influence by environmental, and it also easy get problem, the important is the user can’t adjust water supply and repair by themselves once it broken, this further cause instrument can’t normal working.(See below Figure 5):

Figure 5: The RED color part is Electronic Humidity Sensor

3、 Our product equipped a water purification device, customer can use a water pipe connect it to provide water supply directly, meantime, it also equipped a linkage solenoid valve which control by PLC control panel to prevent over water supply and can to do automatic to do water supply. But our competitor usually use a water tank which often lack of water and caused testing terminated. (See below Figure 6):

Figure 6: The RED color part is Linkage Solenoid Valve; The BLUE color parts is Water Purification Device(One is as backup).

4、 Our temperature climatic chamber’s key electrical connector parts adopted with famous brand AC contactor and solid state relays from Schneider and Omron brands. (See below Figure 7):

Figure 7: Schneider and Omron brands AC contactor and solid state relays

5、 For some customer need to do high temperature and high humidity test at same time(For example: both 70°C temperature and 70% humidity test), besides we provide standad rubber stopper, we also will provide extra high pressure release tube, if without pressure release tube, it may cause both temperature and humidity can’t reach up to setted value and further influence final test result. (See below Figure 8):

Figure 8: The RED color part is Pressure Release Tube

Based on above new design and technology application, Lisun high/low temperature and humidity test chamber has sold to worldwide and accepted by many famous company and ISO/IEC 17025 accreditation test laboratory, our products can fully meet all kind of environmental test requirement.

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Contactor Installation

Contactors are usually selected, sized and ordered by their intended full load amperage. It is usually OK to oversize a contactor, but never to undersize it. Some users try to limit their selections to minimize the number of parts ordered, even if they oversize a component once in a while.

Small contactors may use DIN rail mounting, and some contactors use their own specialized mounting plates or can simply be panel-mounted. Bigger contactors are quite heavy and usually must be bolted to an enclosure backpanel. Note that while industrial relays often are removable and plugged into permanently wired bases, this is not usually the case with contactors. Contactors are typically mounted and wired into place and must be unbolted and unwired when replaced (Figure 4). Sometimes a contactor can be disassembled from the front for replacing certain parts.

Most small relays are designed to be IP20 touch-safe as are some newer contactors, especially IEC versions. However, many larger contactors will have open-style configurations requiring separate terminal covers. Wires are either landed into compression lugs or sometimes lugs must be installed onto the wires so they can be landed on bolted connections. Some vendors offer ready-made jumper bars to speed electrical installation for various configurations. Other helpful features are clearly marked connections and model number, and a means to easily apply nameplates or markers.

One final note regards using contactors with PLC discrete outputs. If a small contactor is to be directly controlled by a PLC, then a coil surge suppressor should be installed on the contactor to protect the PLC output from failure. For larger contactors the coil is likely too big to be energized by the PLC directly, so a PLC relay output or an interposing control relay may be needed. Many manufacturers offer electronic coils on larger frame contactors, which reduce the energizing current allowing for direct control without an interposing relay.

Contactors as Motor Starters

Motors are a special category of load, and the NEC has certain requirements for overcurrent and overload protection of motors. When a contactor is used for motor control, it is typically combined with an overload relay to provide better protection for the motor and feeder wiring. Contactors paired with an overload relay in this way and used in motor control service are often called starters (Figure 5). If a contactor is bought as an assembled package with an overload relay, it may be called a combination starter.

Contactors are versatile devices used widely in a variety of industries. Although simple in concept, there are many nuances that must be understood to properly specify and apply contactors.