• 1. How do I select the correct TIR Trip Indication Relay for my application? Open or Close

    Selection of the correct TIR for a specific application is relatively simple.  First, select the part number range of the TIRs with the desired contact configuration and rating.  TIRs are available in 1 Form C,  1 Form A or 2 Form A contact configurations.   Each is available in different contact ratings.  For example, if a 1 Form C contact is required to switch 125V at 0.25 amps (31.25 Watts) , the catalog sheet shows that TIR part numbers  6319201 – 6319206 meet this requirement.

    Next, select the relay with the highest “Operate Current” rating that is equal to or less than the nominal current for your circuit.  For instance, if the circuit has a nominal current of 4.6 amps, in the 6319201 to 6319206 range,  P/N 6319202 is appropriate for this application.  Because P/N 6319202 has a maximum continuous current rating of 10 amps, there is no danger of damage to the relay coil even if there are large current surges or a sustained current well above the 2.5 amp nominal rating.  This selection method is the most conservative because it results in the highest maximum current rating and lowest insertion loss (coil resistance) for the circuit.

    A variety of “Special Application” relays are available.  Please contact E-MAX for For additional ratings and contact configurations.

  • 2. What is the Difference Between the Type RAW and Type CM Relays? Open or Close

    The E-max Type RAW (and RAW-1D) and Type CM (and Type CMD) Trip Circuit Monitors are physically and functionally similar.  There is one internal connection that changes the operation of the CM, shown in the diagram below:

    As the diagram shows, in the Type RAW and RAW-1D relays (red connection), the LED is lit when the relay is energized through Terminals 1 & 2, but bypassed when the relay is energized through Terminals 1 & 3.  In the Type CM and CMD relays (blue connection), the LED is lit when the relay is energized through Terminals 1 & 2, or when the relay is energized through Terminals 1 & 3.

    This diagram illustrates the difference in operation in a typical application.





  • 3. What are the Torque Specifications for E-MAX Small Relays and Diode Assemblies? Open or Close

    The terminal studs of all E-max Small Relays and Diode Assemblies are made of nickel-plated brass.  The recommended torque values are different for the two stud terminal sizes.

    The maximum recommended torque for 10-32 size terminal studs  is 25.9 inch-lbs.

    The maximum recommended torque for 6-32 size terminal studs is 7.9 inch-lbs.

    These values coincide with industry standard maximum torque recommendations for hardware of these types and sizes, and have been tested on these devices.

  • 4. Are the LED’s in the RAW-1, RAW-1D, CM and CMD replaceable? Open or Close

    Yes, the LEDs are easily field replaceable.  Installation Instructions are available by clicking the LED Installation document.

  • 5. What is the Warranty Policy for E-MAX Instruments? Open or Close

    To view or print the Warranty Policy, click on the E-MAX Warranty Policy document.

  • 6. The substation GPS receiver was replaced recently and now the E-MAX DFR's clock won't sync. Why? What can I do about this? Open or Close

    If the DFR clock doesn't synchronize to a new GPS receiver's IRIG-B output, there are two possible  reasons:

    1. The signal output of the new receiver does not match the DFR clock's configuration;

    2. The signal amplitude of the IRIG-B signal from the new receiver is lower than that of the original.

    To troubleshoot this problem, first verify the signal type (IRIG-B modulated or TTL) now being applied to the DFR.  If possible, compare this to the way the old receiver was set.  If they do not match, the DFR clock must be reconfigured to accept the new signal.  If information regarding the input signal is not available, check the DFR's configuration to verify that it is correct for the signal now being received.  Information on E-MAX DFR clock configuration is available in the system manual, through the E-MAX ShareFile ftp site (available to registered users), or from E-MAX Tech Support.

    If the configuration is correct, and the DFR clock still does not sync, it may be due to the signal from the new receiver being of a lower amplitude than the older one.  In this case, it may be possible to adjust the clock to increase its sensitivity.  Note: This adjustment is available on both the P/N 036D772-773 clock boards, and the 037D651-652 Multifunction Interface Card with IRIG.

    To increase the clock's signal sensitivity, locate the appropriate potentiometer (R39 on P/N 036D772 and 036D773; R15 on P/N 037D651 and 037D752).  Adjust this pot to full counterclockwise.  Test to verify that the DFR now syncs to the time of the GPS receiver. 

  • 7. What’s the difference between Type TIR and Type AVR Relays? Open or Close

    E-MAX Type TIR and Type AVR Relays are specialized high-speed electromechanical relays designed for use in power utility and industrial control applications.   They are extremely rugged and are designed for harsh environments.

    The TIR and AVR Relays share many physical characteristics; however, they are functionally at two extreme ends of the spectrum of operating characteristics for electromechanical relays.

    The Type TIR relays are designed to be connected in series with a current-operated device, such as a lock-out relay coil or circuit breaker coil.  They are built with high-current (but very low resistance) coils so that they can be connected in series with the relay or breaker coil and not affect its operation.

    The Type AVR relays are designed to be connected in parallel with voltage-operated devices.  They are built with very high resistance (but very low current) coils so that they can be connected in parallel with other voltage-operated devices and not affect their operation.