LJ Relays (Technical Specifications and Ratings)

TECHNICAL SPECIFICATIONS AND RATINGS

Contacts
The four millisecond LJ relay is furnished from the factory with any customer specified combination of normally open or normally closed contacts in the field, if necessary. These all silver contacts can carry 30 amps DC for one second, 5 amps DC continuously, and are double make/break in order to ensure reliable operation.

The normally open contacts are designed to close within 35% of armature travel. The remaining armature travel ensures good contact wipe and minimizes bounce. In order to further ensure contact cleanliness, each contact is individually encased in clear plastic to prevent external contaminates from building up during periods of non-use.

LJ Relay Case Features
LJ relay enclosures are designed and constructed to seal the relay and protect the contacts and coil from exposure to external dust, fly ash and similar contamination. This is accomplished with a special gasketing system and the application of a special epoxy along the seams of the case.

To beter meet the needs of a utility, three different mounting configurations are available - flush mount with target and optional test switches, projection mount with target, and a caseless projection mount with target (LJ4x series). As an extra security feature, the optional Weidmuller test switches cannot be left open when their cover is fully closed. By design, the LJ relay can be manually operated in its enclosure.*

The Relay Associates standard semi-flush enclosure (type E) has a remarkably small panel cutout (3"x5" for the 6 contact unit without test switches). However, it is also available in a semi-flush enclosure with a larger front panel for mounting in a ABB FT-11 cutout or a GE HFA non-drawout cutout.

Seal-In with Manual Reset Option
An electrical seal-in with manual reset version of the LJ relay is available for "lockout" applications. Reset is accomplished by depressing a small pushbutton which is mounted on the front of the relay panel. This application requires a continuous DC voltage source (same voltage as relay rating) and reduces the number of usable contact by one.

LJ relays have successfully passed the Dielectric Tests Across Open Contacts, the Surge Withstand Capability (SWC) Tests and the Fast Transient Test requirements as specified in ANSI/IEEE C37.90.

The LJ relay high burden operate coil design provides immunity to misoperation from accidental grounding of coil/battery wiring. LJ relays rated @ 125 Vdc require greater than 0.61 joules capacitive discharge energy to induces a momentary contact closure. This is equivalent to discharging the energy of a 200 microfarad capacitor charged to 78 Vdc.

LJ Relay Contact Rating

	Inductive Interrupting Rating * (138 Voltamperes with L/R = 0.100)		Contact Current Rating
Contact Circuit **	Single Contact	Double Contact	Short Time (1 sec)	Continuous
48 Vdc	2.9A	10A	30A	5A
125 Vdc	1.1A	5A	30A	5A
250 Vdc	.28 ***	1A***	30A	5A

* The inductive interrupting rating was determined by testing to NEMA ICS 5 standards. Although NEMA test standards do not establish the resistive interrupting rating, independent test results have shown no apparent contact degradation when interrupting 4 amps resistive current @ 125 Vdc and 2 amps @ 250 Vdc.
** For ac ratings, contact Relay Associates.
*** Derated due to reduced NEMA rating designation.

Operating Data for Continuously Rated LJ Relays

Coil Circuit	Operate Coils Resistance @ 20° C	Hold Coil Resistance @ 20º C	Typical Operate Time * (Normally Open Contact) Pickup Dropout		Operating Voltage * Must Must Pickup Dropout
48 Vdc	1.90 W+5%	236 W +7%	4.5 ms + 0.5	<15ms	38 Vdc	5 Vdc
125 Vdc	13.0 W +5%	1490 W +9%	4.5 ms + 0.5	<15ms	100 Vdc	15 Vdc
250 Vdc	52.0 W +5%	8700 W +15%	4.5 ms + 0.5	<15ms	200 Vdc	30 Vdc

* Operating time values and pickup/dropout voltage values are measured with relay "hot" in accordance with ANSI/IEEE C37.90 standard. Typically, the "must pickup voltage" will be 10 lower for "cold" relay.

Contact Relay Associates for more information.