Panel meter for temperature control HT950N User’s manual Copyright HT-ITALIA 2003 Release EN 1.
HT950N Index: 1. SAFETY PRECAUTIONS AND PROCEDURES ...................................................................... 3 1.1. 1.2. 2. 3. GENERAL DESCRIPTION ....................................................................................................... 4 PREPARATION TO USE .......................................................................................................... 4 3.1. 3.2. 3.3. 3.4. 4. Initial ..................................................................................
HT950N 1. SAFETY PRECAUTIONS AND PROCEDURES This meter is designed in conformity to EN61010 standards relating to electronic measuring instruments. For your own safety and that of the apparatus, you must follow the procedures described in this instruction manual and specially read all the notes preceded by the symbol carefully. Strictly keep to the following instructions before and during measurements: Do not install the meter in environments with explosive gas, fuels or dust.
HT950N 2. GENERAL DESCRIPTION Dear Customer, we thank you for your patronage. The HT950N meter you have just purchased will grant you accurate and reliable measurements, on protection of MV transformer, provided that it is used according to the present manual’s instructions. The HT950N model it was been designed with high quality electrical components and, during test verify, it’s subject to BURN-IN test to eliminate any internal bugs due to rapid death rate of components.
HT950N 4. OPERATING INSTRUCTIONS 4.1. DESCRIPTION FRONT PANEL LEGEND: 1. Principal Display 2. PARAmeters Display 3. SET Display 4. Function keys HT950N Controller Fig. 1: Instrument description, frontal view CONTROL Led The light on of this Led mean that temperature of one of four inputs is over the setting UA threshold value and the CONTR output relay is closed. This can active the start of forced ventilation system or a parallel device.
HT950N T2 Led This Led shows that measured temperature by one of four probes is over T2 alarm threshold set on HT950N and correspondent relay is activated. This means transformer turn off (see Fig. 9). T.MAX Led This Led is light on when you press T.MAX key and show the maximum temperature recording by HT950N during all measured period. SET display shows the temperature value and PARA display shows the column (C1=2U, C2=2V, C3=2W, C4=1F) of correspondent maximum value.
HT950N T.MAX key Press this key the meter show at PARA display the column symbol (C1, C2, C3, C4) which have the maximum temperature value during all measure period. SET display show instead the value of recording temperature. T.MAX Led is light on during operation. After about 20 sec. from pressing of T.MAX key PARA and SET displays automatically light off. T.MAX key is also used for reset temperature maximum value (see chapter 5.4. for details). WARNING T.
HT950N 5. OPERATIVE INSTRUCTIONS 5.1. INSTALLATION For HT950N practice installation please consider the following specifications: Installation zone must to be dust and corrosive gas free. HT950N meter must to be installed: Far from direct solar light and impact warm sources; Far from MV devices (big meter counter, energy cables, SCR or TRIAC apparatus, radiotransmitter). You must prepare a square hole on 36.8 x 36.8 inch (height x width).
HT950N 5.2.1. Power supply circuit HT950N meter can be supplied with AC (50/60Hz frequency) or DC sources. If you use DC supply please connect positive (+) and negative (-) contact at terminals 30 and 32 respectively, like shown on Fig. 4 Fig. 4: Power supply terminals of HT950N WARNING Use a cable with section 1mm2 for power supply the meter. Its necessary to insert a easy to reach voltage protection switch on/off before HT950N to interrupt voltage. The EMC levels/immunity declared in chapter 7.
HT950N 5.2.2. Temperature probes WARNING Input circuits (2U, 2V, 2W, 1F) operates with small signals therefore its necessary to execute a separated wiring from relay command output circuits, supply circuit and from other power circuit. We always recommended to connect of each Pt100 to use a shielded cable with shield connected from meter front only. Connect at S terminal (31) the shield of each thermoresistance, like shown on Fig. 3.
HT950N 5.2.4. T1 output alarm circuit The output relay connection of T1 pre-alarm circuit is presented on following Fig. 7: Fig. 7: T1 relay on no alarm conditions (normally activated) T1 relay operate a commutation in the following cases: When HT950N measures a temperature over T1 threshold. Whit Pt100 probes open or shorted. Power supply switch off on HT950N. 5.2.5. T2 output alarm circuit The output relay connection of T2 alarm circuit is presented on following Fig. 8: Fig.
HT950N 5.4. SETUP OF ALARM THRESHOLDS On HT950N meter it’s possible to set up to four alarm thresholds with values within all measure range. The sequence of programmable parameters presented cyclically by meter is the following: T2 T1 UF UA Parameters setup is possible using PARA and arrows keys [], [], [] with the following procedure: 1. Power on HT950N meter. 2. Press PARA key. On PARA display appear “t2” message and on SET display is shown the last programmed T2 value. 3.
HT950N 5.4.1. Example of HT950N meter setup In the following Fig. 9 is possible to see a simple example diagram with programmable parameters T1, T1, UA, UF, with relative meaning. Fig. 9: Example of HT950N meter setup 5.5. CLEAR OF RECORDED MAX TEMPERATURE VALUE To execute clear of maximum value of temperature recorded by HT950N meter, do the following procedure: 1. Press T.MAX key to show the maximum temperature value on PARA and SET display. 2. Press [] key before both display lights off.
HT950N 5.6. SETUP OF INPUT PROBES NUMBER Default internal setup of HT950N meter consists on activation of 3 Pt100 probes only (2U, 2V, 2W). To modify this number operate in following way: Press PARA key until message C_End compare on SET display. Press [] key. On SET display the digit “d” starts to blinking. Press [] or [] key and setting the “111” number onset display. Press ENT. key to confirm.
HT950N 7. TECHNICAL SPECIFICATIONS 7.1. TECHNICAL CHARACTERISTICS 7.1.1. Inputs characteristics Inputs: from 1 to 4 PT100 DIN 3-wires Accuracy: (0.5% rdg + 1dgt) Range: 0 200°C Compensation line resistance: automatically 7.1.2. Output characteristics Outputs: Current:: Nominal voltage: Max. commutable voltage: Nominal AC1 power : 3 independent relays free of voltage 5A 250 V 250 V 1250 VA 7.1.3.
HT950N 8. SERVICE 8.1. WARRANTY CONDITIONS This equipment is guaranteed against material faults or production defects, in accordance with the general sales conditions. During the warranty period (one year), faulty parts may be replaced. The manufacturer reserves the right to decide either to repair or replace the product. In case of returning of the instrument, all transport charges must be paid by the customer.
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