Description
The STS replacement relay is a 2 form C contact arrangement used in the STS 300 Ground Monitoring System. You can use it for industrial and motor controls to connect additional accessories, such as programmable logic controllers (PLCs), alarms and lights. Relays are specified by system voltage.
What the relay does
On the STS 300, the dry contacts change state when a proper ground is established: normally open contacts close and normally closed contacts open, permitting pumps or valves to operate through your interlocking control contactors. Per the STS 300 manual, connect the contacts to interlocking control contactors and do not connect them directly to motor loads.
Specifications
| Contact arrangement | 2 form C |
| Contact rating | 15 A, 120 VAC; 10 A, 277 VAC; 15 A, 30 VDC |
| Voltages | 12 VDC, 24 VDC, 120 VAC, 240 VAC |
| Part number | Voltage | Grounding system |
|---|---|---|
| RL-12 | 12 VDC | G12 |
| RL-24 | 24 VDC | G24 |
| RL-120 | 120 VAC | G2 |
| RL-240 | 240 VAC | G4 |
When to replace the relay
The STS 300 maintenance schedule includes inspecting the relay contacts and internals for corrosion or water damage. Replace the relay if it shows corrosion or water damage, or if STS support identifies it as the cause of a fault. See the STS 300 installation and operating manual (PDF) for the full schedule and troubleshooting table.
Compatible products
FAQ
Which relay do I need?
Order the relay that matches your system voltage, shown on the nameplate and in the model number (G2, G4, G12 or G24).
Can I connect a PLC to the STS 300?
Yes. The relay contacts can be used to connect accessories such as PLCs, alarms and lights.
Not sure which part fits your unit? Request a quote with your STS 300 model number and STS will confirm the part.
