RIBU1C Enclosed Relay 10Amp Wiring Diagram

RIBU1C Enclosed Relay 10Amp Wiring Diagram

RIBU1C Enclosed Relay 10Amp Wiring Diagram

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Typical RIBU1C hookup

Choose the coil input; tap any wire to see how it connects.

Typical RIBU1C hookup
RIBU1CWHT/BLK120 V ACCAPCONTROLLEROR THERMOSTATPOWERUP TO 28 V DCOR 277 V ACWHT/BLU10-30 V AC/DCWHT/YELCOMMONBLU · N/CNOT USED (OR POWER)YEL · CORG · N/OLIGHT OROTHER LOADCOMMON OR NEUTRALRIBU1CWHT/BLU10-30 V AC/DCCAPCONTROLLEROR THERMOSTATPOWERUP TO 28 V DCOR 277 V ACWHT/BLK120 V ACWHT/YELCOMMONBLU · N/CNOT USED (OR POWER)YEL · CORG · N/OLIGHT OROTHER LOADCOMMON OR NEUTRAL

Terminals and components · 8

  • 10-30 V coil
  • Coil common
  • C
  • N/O
  • N/C
  • Load

About This Diagram

This diagram is redrawn from page 1 of the RIBU1C Enclosed Relay 10Amp manual, and we offer it completely free and in English. We have also categorized it in the Control Relays & Timers (Motors & Industrial) section on Diagramverse, and it has been rated by 1 user with an average rating of 5.0. If you have any specific questions about the RIBU1C Enclosed Relay 10Amp Wiring Diagram, we suggest checking the Frequently Asked Questions (FAQs) section.

Printable RIBU1C 10Amp Wiring Diagrams

10-30 V coil

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RIBU1C Enclosed Relay 10Amp Wiring Diagram – 10-30 V coil
RIBU1C Enclosed Relay 10Amp Wiring Diagram – 120 V AC coil

Wiring Instructions

Before you start

The RIBU1C 10Amp lets a low-power controller or thermostat switch a separate load. It has two separate circuits, so plan each one before you begin. The coil side uses Wht/Blu, Wht/Blk and Wht/Yel. The contact side uses Yel (C), Org (N/O) and Blu (N/C).

Pick the diagram variant that matches the control voltage your controller supplies:

  • 10-30 V coil: use this variant if the controller or thermostat puts out 10-30 V AC or DC, for example a 24 V AC thermostat or a 12 or 24 V DC building automation output.
  • 120 V AC coil: use this variant if the control signal is 120 V AC.

Use only one coil input, never both. Before you buy or wire anything, confirm that the load is within the contact ratings. The contacts handle 10 A resistive at up to 277 V AC or 28 V DC. Motor, tungsten and ballast loads have lower ratings, and the N/C contact has lower tungsten and horsepower ratings than the N/O contact. The relay is not rated for electronic ballasts.

Tools and materials: a non-contact voltage tester, a multimeter that reads AC and DC volts and continuity, wire strippers, wire connectors rated for the conductor sizes and count you are joining, and a junction box with a 1/2 inch knockout for the 0.50 inch NPT hub. The relay's leads are 16 inches long and rated 600 V. Size the field conductors of the load circuit for the load current and the overcurrent device that protects that circuit. If you are unsure, follow your local code or ask an electrician.

Isolation: turn off and lock out the breaker for the load circuit. Also turn off the controller's power, or its transformer. A 120 V AC control circuit is line voltage, so treat it that way.

Line-voltage work, new circuits, and any installation in a fire alarm system (the RIBU1C-RD version) should be done by a licensed electrician. Many jurisdictions require a permit for this work.

Step-by-step wiring

  1. Mount the relay by its 0.50 inch NPT hub through a knockout in a junction box, so all leads and splices end up inside the box. Use the standard grey housing indoors in dry locations. Use the RIBU1C-N4 where you need a NEMA 4 housing.
  2. Confirm that power is off at both the controller and the load circuit, using your tester on the conductors you will touch.
  3. Connect Wht/Yel (coil common) to the controller's common, or to neutral for a 120 V AC control circuit.
  4. Connect the coil input that matches your variant to the controller's switched output. Use Wht/Blu for 10-30 V AC/DC or Wht/Blk for 120 V AC.
  5. Cap the unused coil lead on its own with a wire connector. Do not leave its bare end loose in the box.
  6. Connect Org (N/O) to the hot side of the load power source.
  7. Connect Yel (C) to the load. This is the switched leg out to the light or other load.
  8. Connect the load's other side to the source neutral or common, not to the relay.
  9. If you are not using Blu (N/C), cap it individually. Use Blu only if the load should run while the coil is off, and then check its lower tungsten and horsepower ratings.
  10. Tug-test every splice. Keep the low-voltage control wiring separated from the line-voltage load wiring, as your local code requires, then close the box.

Testing and start-up

Restore power to the controller first, with the load breaker still off.

  • Command the controller on. The LED on the relay should light, because LED on means the relay is activated.
  • Measure the voltage between the coil input you used and Wht/Yel. It should be at least the pull-in voltage of 9 V AC or 10 V DC on the low-voltage input, or close to 120 V AC on Wht/Blk.
  • Command the controller off. The LED should go out, and the coil voltage should fall below the drop-out voltage of 2.1 V AC or 2.8 V DC.
  • With the load still unpowered, check continuity. Yel to Org should close when the coil is on. Yel to Blu should close when the coil is off.
  • Turn the load breaker on and cycle the controller a few times. The load should follow the command, and the relay should switch cleanly with no buzzing.

Safety notes

  • The load contacts can carry up to 277 V AC. Even when the coil is off, the Org lead (and the Blu lead, if used) stays live whenever the load breaker is on.
  • On the 120 V AC coil variant, the coil circuit is also line voltage. Isolate it separately from the load circuit.
  • Never exceed 10 A on the contacts. For motors, tungsten lamps and ballasts, use the matching lower rating, and do not use the relay with electronic ballasts.
  • Install the relay only within -30 to 140°F and 5 to 95% humidity, noncondensing, and choose a housing rated for the location.
  • The relay has no manual override switch. To test the load without the controller, use a proper control-voltage source, not a jumper across live contacts.

Troubleshooting

Symptom Probable Cause What to Check
The LED never lights and the load never turns on No control voltage at the coil, the wrong coil lead is used, or Wht/Yel is not connected to the controller common Measure between the coil input you used and Wht/Yel while the controller is calling. You should read 10-30 V on Wht/Blu, or about 120 V AC on Wht/Blk. If you read nothing, check the controller output and the Wht/Yel return.
The relay buzzes, chatters or clicks on and off Control voltage below pull-in, or an overloaded or undersized control transformer Measure the coil voltage while the relay is energized. It must stay above 9 V AC or 10 V DC on the 10-30 V input. Check that the transformer can supply the coil current, for example about 46 mA at 24 V AC, plus its other loads.
The LED stays on, or the relay will not release, when the controller turns off Leakage voltage from a solid-state or triac controller output With the controller commanded off, measure across the coil input and Wht/Yel. Anything above 2.1 V AC or 2.8 V DC can hold the relay in. Use a dry-contact output, or ask the controller maker how to handle leakage.
The load runs when it should be off and stops when it should run Load supply connected to Blu (N/C) instead of Org (N/O) Turn off power and move the load supply from Blu to Org. Then confirm that Yel to Org shows continuity only while the LED is on.
The relay clicks and the LED lights, but the load does nothing No supply on Org, Yel not connected to the load, or the load not returned to neutral or common With the coil energized, measure from Yel to the source neutral or common. You should read the full supply voltage. If you do, trace the load's return conductor. If you do not, check the Org feed and its breaker.
The breaker trips the moment the relay closes Yel or Org connected to neutral, common or ground instead of to the load, which creates a dead short through the contacts Turn off power and verify the path: hot to Org, Yel to the load, and the load to neutral. Check for continuity from Yel to neutral with the load disconnected. There should be none.
The relay died right after power-up on a 120 V control circuit 120 V AC applied to the Wht/Blu low-voltage input Confirm the controller's output voltage. The 120 V AC signal must go to Wht/Blk. If the relay no longer responds, replace it and rewire it correctly.
The load stays on permanently, or the contacts fail early Load beyond the contact rating, such as a large motor, heavy tungsten load or electronic ballast Compare the load nameplate with the ratings: 10 A resistive, 1/3 HP at 120-240 V AC on N/O, 600 W tungsten at 120 V AC on N/O, and no electronic ballasts. Use a contactor for larger loads.
A breaker or the controller fuse trips at random The unused coil lead or Blu lead is uncapped and touching metal or another conductor in the box Turn off power, open the box, and cap each unused lead individually with a wire connector.
The load works intermittently or flickers Loose splice on the stranded relay leads Turn off power, then remake and tug-test each connection. Use connectors sized for the conductor combination.

Frequently Asked Questions (FAQs)


Which coil lead should I use, Wht/Blu or Wht/Blk?
Use Wht/Blu if your control signal is 10-30 V AC or DC, and use Wht/Blk if it is 120 V AC. Wht/Yel is the common for either input and returns to the controller common or neutral. Connect only one coil input and cap the other one individually. Applying 120 V AC to the low-voltage Wht/Blu lead can damage the relay. Measure the controller output before you connect anything if you are not sure what it supplies.

Can a standard 24 V AC thermostat drive the RIBU1C?
Yes. A 24 V AC thermostat output falls within the 10-30 V AC/DC range of the Wht/Blu input. The coil draws about 46 mA at 24 V AC, which is well within the capacity of a typical thermostat transformer. Connect the thermostat's switched terminal to Wht/Blu and the transformer common to Wht/Yel. Make sure the voltage at the coil stays above the 9 V AC pull-in level while the relay is energized.

Can I control the relay with a DC output from a PLC or building automation controller?
Yes. The Wht/Blu input accepts 10-30 V DC as well as AC. It draws about 15 mA at 12 V DC and 18 mA at 24 V DC, so most DC outputs can drive it directly. Pull-in is 10 V DC and drop-out is 2.8 V DC. If your controller has a solid-state output, check that its off-state leakage stays below the drop-out level so the relay releases reliably.

Can the RIBU1C switch a motor?
Yes, for small motors. On the N/O contact it is rated 1/3 HP at 120-240 V AC and 1/4 HP at 277 V AC. The N/C contact is rated lower: 1/6 HP at 120-240 V AC and 1/8 HP at 277 V AC. For anything larger, use the RIBU1C as a pilot relay to switch the coil of a properly sized contactor or motor starter. It is rated 480 VA pilot duty at 240-277 V AC for that purpose.

Can I use it to switch lighting?
Yes, within the ratings. It handles 600 W of tungsten (incandescent) load at 120 V AC on the N/O contact, or 240 W on N/C, and 480 VA of ballast load at 277 V AC. It is not rated for electronic ballasts. For LED drivers and other electronic lighting, check the fixture maker's inrush data, or use a relay or contactor that is specifically rated for that type of load.

Can I switch a 240 V load with this relay?
The contacts are rated up to 277 V AC, so 240 V is within the voltage rating. However, the RIBU1C is single pole, so it can open only one of the two hot legs. The load stays connected to the other energized leg even when it is off. Where both legs must be disconnected, use a double-pole relay or contactor. When in doubt, ask an electrician what your local code requires.

Can I install the RIBU1C outdoors or in a wet area?
Not the standard model. The grey RIBU1C has a NEMA 1 housing, which is meant for indoor, dry locations. For wet, washdown or outdoor locations, choose the RIBU1C-N4, which has a clear NEMA 4 enclosure. Any version must also stay within -30 to 140°F and 5 to 95% noncondensing humidity. Mount it on a box rated for the location as well.

What is the difference between the RIBU1C, RIBU1C-RD and RIBU1C-N4?
All three have the same SPDT relay and the same wiring. The differences are the housing and the approvals. The RIBU1C is grey, NEMA 1 and UL916 listed. The RIBU1C-RD is red, NEMA 1 and UL864 listed with California State Fire Marshal approval, which suits fire alarm applications. The RIBU1C-N4 is clear, NEMA 4 and UL508 listed. All three are accepted for use in plenum spaces.

Can I mount the relay in a plenum space above a ceiling?
Yes. Every RIBU1C version is accepted for use in plenum spaces. The rest of the installation still has to be suitable for a plenum, including the box, the cable and the method used to mount and support it. Mount the relay through a knockout with its 0.50 inch NPT hub so the leads and splices stay inside the box.

Does the RIBU1C have a manual override or a status indicator?
It has a status indicator but no manual override switch. The LED lights when the relay is activated, meaning the coil is energized and the N/O contact is closed to common. To operate the load without the controller, you must supply the correct control voltage to the coil input. Do not jumper the contacts on a live circuit.

What does the N/C contact do, and when would I use it?
The Blu (N/C) lead is connected to Yel (C) whenever the coil is off and opens when the coil energizes. Use it when a load should run by default and stop when the controller calls, such as a fail-safe or alternating function. Its ratings for tungsten and motor loads are lower than those of the N/O contact. If you don't use it, cap it individually.

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