Description
Product details
1. Diligent Protector for AC applications Diligent AC relays are available for Over Load (OL), Single Phasing (SP), Phase Reversal (PR), etc. The overload relays are available in 1ph and 3ph types. 1ph-relays are useful on single phase load and can also used as economical solution for 3 ph applications whenever load is balanced. These are classified depending on the response to the overload condition and the classification is as follows - a. INStantaneous (INS) type. In this relay changes the state as soon as overload occurs. b. Time-Delayed (DLY) type. In this the relay changes the state only after elapse of present period from the time overload occurred & stayed. c. Jam (JAM) type. In this, the control relay does not respond to the overload condition for a preset time from switching on the load but after elapse of this time, the relay responds immediately to any overload. MICRO CONTROLS 2 Instantaneous type is primarily made for AC loads other then motor such as: transformer, heater etc. However, it has been also used along with other logic to control motor. Time-Delayed overload relay find wide use. The tie delay provided in the relay avoids nuisance tripping in response to transient overloads but switches off the load if overload persists beyond the specified time. Most of the loads in actual practice increase temporarily and the drive is usually designed to handle this type of overloads. Jam type overload relay is quite unique and has made possible very reliable protection of loads such as Blower, Fans, Stirrer motors which was rather difficult to achieve with conventional thermal relay. Jam relay not only saves the motor, but restricts the possible damage to the equipment & loss of production by advance intimation before catastrophic failure takes place. Such situation, for example, can arise when ‘oil-starved bearings’ starts slowly seizing and if not attended in time can get heated and tear out the housing. Repair not only costs in term of money but looses precious time. Similarly, jamming of conveyor can be effectively responded by the Jam relay and catastrophic failure there of can be averted. Single Phasing (SP) protection in Diligent Protector relay is either Current Operated Single Phasing (COSP) or Voltage Operated Single Phasing (VOSP). COSP is realised by sensing each of the phase current continuously. As soon as current in any one phase is lost, control relay changes the state. This greatly limits the heavy thermal stresses due to large current flowing in the connected phase-windings of motor. VOSP protection monitors all three supply phases and acts when one of the phases of 3 phase supply is missing. However, Should phase be lost while 3 phase motor has already running, VOSP may not trip the motor because of the induced voltage in the motor winding. However, COSP is effective even when the phase is lost while the motor is in operation. 2. Diligent Protectors for DC Applications Diligent Micro Controls has also developed protection relays for DC loads such as DC motor, DC generator, Rectifier sets, DC electromagnet etc. These relays are available in three types: namely INStantaneous, Time-Delayed and Jam type similar to the AC relays. DC relay operates from “75 mV standard DC shunt” and requires auxiliary supply for its operation. Optionally the relay can be made suitable to work with User-specified shunt. 3. Diligent Protectors for AC or DC Under-/ Over-Voltage Diligent Protector for AC or DC Under-/Over-Voltage fault is designed to monitor the voltage level continuously and whenever it exceeds set limits for more than the set time, the relay inside picks up. This relay can be made auto reset type or manual reset type. 4. Diligent Protector for Neutral-Earth Voltage Diligent Protector for Neutral-Earth voltage monitors this voltage continuously and whenever it exceeds set limits for more than the set time, the relay inside picks up. This relay can be made auto reset type or manual reset type. 5. Diligent Protector for Conveyor Jamming Diligent Protector for jamming of conveyor is unique. It allows conveyor motor to start normally and monitors continuously current drawn by it during operation. It trips the motor immediately when current exceeds the set JAM limit. This averts catastrophic failure and consequential loss of production. This relay can be made auto reset type or manual reset type. 6. Diligent Protector Shear Pin Replacement Diligent Protector for shear pin replacement is unique. Shear pin disengages the motor from the load by breaking itself when load increases beyond the permissible level. However, replacement of shear pin is associated with inherent uncertainties of material quality. This renders shear pin protection less reliable. Diligent Protector Replacement for shear pin is unique. Not only it provides precise and repeatable protection but it also has provision to adjust the protection level which enables to match the protection to the load. This relay can be made auto reset type or manual reset type. 7. Diligent Protector for Lifting Electromagnet Diligent Protector for Lifting Electromagnet allows electromagnet to be switched on under normal condition but when its current drops below the set level for more than prescribed period, Diligent Protector alarms the operator. 8. Diligent Protector for Grinder Under-/Over-load This is very special type of protection. Whenever grinders are working with full charge, it draws large current initially and drops as grinding completes. Any prolonged operation after completing grinding, the material can burn due to over heating as well as energy will be consumed without any useful work. Diligent Protector for ‘Grinder Under load’ will trip the motor as soon as current drops below the set limit. 9. Diligent Unique Protector for Blower / Fan Conventional Overload protection is not at all suitable for Blower / Fans due to their starting characteristic. Diligent Unique Protector for Blower / Fan is really unique. It allows normal blower start up successfully; however, if blower motor draws more current than set limit, it immediately trips the motor. This is very useful as blower/fan is most ignored equipment in most of the industries and they suffer consequential catastrophic failure due to this negligence. Diligent Protector will trip the blower even at the onset of faults such as starving for lubrication, impeller unbalance, excessive vibration, interference due to broken parts, etc. 10. Diligent Monitor for Solenoid Coil Solenoid valves are very critical in the process control and their healthiness is of utmost importance. Diligent Monitor for Solenoid Valve, monitors the healthiness of solenoid coil during operation. Should coil become open during operation, a potential-free contact closes to transfer this information to centralized SKADA system or sound an alarm. 11. Diligent Monitor for Heater In some applications like sterilizing system in pharmaceutical industries, numbers of electric heater elements are used in banks to achieve acceptable sterilizing temperature. However, failure of some elements does not become known until when finished goods start getting rejected during quality control. Loss is large at this stage. Diligent Heater Monitor gives alarm when number of available heater drop below the acceptable number. 12. Auxiliary Supply: Standard auxiliary supply 230V, 110V, 24V AC or 24V DC can be specified. Relays can be made to operate on any other user-specified supply. 4 13. Output Contact: One Change-over contact rated at 4 Amps (resistive) at 230V ac, is provided. This contact stays in actuated state as long as long fault does not exist. 14. Status & Fault Display: Relay carried unique display which indicates various status and also the fault on which the load has been switched off. It also has LED which glows steady under normal condition but starts flashing when relay trips. This is very useful feature where the tripped relay has to be spotted among the cluster of relays & contactors. This along with the type of fault indication immensely simplifies fault diagnosis by identifying the defaulted zone. This results in considerable reduction in MTTR (Mean Time to Repair) and improving system availability. 15. Post Fault Reset: Relay tripped in response to the fault, has to be restored for normal use again. Depending in the nature of fault and requirement of particular application, this restoring can be effected either automatically (AUTO) or manually (MAN) or combination of auto-manual (A/M). The faults which are not serious are cleared by known corrective action and the relay in such case is made to reset by itself or clearing the fault. Operator does not have to go to control panel to reset the relay and he can switch on the load. Such faults are, for example, phase reversal, normal overload etc. However, serious faults, such as, single phasing, mechanical jamming, bearing seizure, short circuit etc. required to be properly investigated before switching on the load again. Hence in such cases, relay is designed to disallow restart unless relay is manually reset by an operator-in-charge. The 3rd type of ‘fault reset’ is very interesting since Diligent Relays combine multiple protection in single unit. Some protection feature could be serious while other may not. It is possible to built user-specified combination of reset logic in our relay. Thus, the relay is made very user-friendly. 16. Warranty: “Diligent Protection Relay carries warranty for a period of twelve months from the day of delivery from our works. During this period, we undertake to repair/replace our defective unit free of cost in part or full at our total desecration provided that the unit is brought to our works for rectification and collected there from after satisfactory inspection by the Customer at his cost & risk and provided that the defect is found to be due to poor material and / or workmanship and not due to misuse and/or mishandling. This warranty is exclusively restricted to the unit supplied by us and we shall not be responsible in any way for any of the consequences arising due to the use and/or misuse of our unit anywhere. This warranty shall become automatically null & void, if our unit is opened and / or tampered by person not authorised by us.”
