Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. It only takes a minute to sign up.
Sign up to join this community
I ordered several OMRON “ice cube” 110 VAC relays, contacts rated for 10A (LY2NJ). When I inspected them under a microscope I noticed the contact wires are AWG 24. The rest of my setup uses AWG 18. My gut instinct was to open the relays and solder in some short runs of the AWG 18 patch wire. Was this overkill or prudent? I do require switching 10 A.
The left relay is the original. The right relay with the red wire is the modified relay.
You have about 30 mm of wire there. A quick check on a couple of online calculators shows that 30 mm of 24 AWG will have a resistance of about 3 mΩ.
From \$ P = I^2R \$ we get power dissipation will be \$ 10^2 \times 0.003 = 300\ \text {mW} \$. I don't think you'll have a problem there. (The 12 V DV version has 160 Ω coil which will dissipate 900 mW.)
Voltage drop will be \$ V = IR = 10 \times 0.003 = 30 \ \text {mV} \$.
This page comes up second in a search for fake OMRON relays marked "ONROM" (a brand name clearly meant to deceive).
The weak point in these relays is not the wire gauge - as noted in the accepted answer - but in the cheap alloy used to make the contacts.
My experience with a sample size of 10 (tricked into buying, like OP) is that contacts will endure perhaps several hundred cycles as long as they carry only control-level current (~100mA or less).
Contacts that carry load current of even just a few amps will fail in less than 200 cycles. My lot also included one with a bad coil (10% failure rate, but not conclusive due to small sample size).
@Drakes, please post your failure modes and stats.
Those wires are connected to the coil, not the contacts. The coil doesn't require 10A.
