Wiring for a Medium-Current Relay SPST-NO, 4 Terminals, 24V DC Input

Thread Starter

EVILPENGUIN

Joined Feb 10, 2023
2
Hello all,

I am new to this forum and would like help with this item.

I am a student working on an electronics project. I am trying to figure out where on this relay I am supposed to wire to. It is from McMaster and they say the wire connection type uses a screw terminal. Could someone show where I'm supposed to unscrew and attach the wiring to? Inserted below is the circuit and an image of the relay and the link to the McMaster part.

https://www.mcmaster.com/7384K16/

IMG_0744.JPGIMG_0749.JPG
IMG_0745.JPGWiringCircuit.png
 

MaxHeadRoom

Joined Jul 18, 2013
28,824
The two screw terminals at the base of the coil , are the coil terminals , the two larger screws on the top of the relay either side of the contacts are where the load is connected that you which to switch.
 

Thread Starter

EVILPENGUIN

Joined Feb 10, 2023
2
The two screw terminals at the base of the coil , are the coil terminals , the two larger screws on the top of the relay either side of the contacts are where the load is connected that you which to switch.
Diagram1.png
Is this what you are describing? Would I just unscrew those screws and then wrap or solder the wire onto them?
 

sghioto

Joined Dec 31, 2017
5,427
That looks correct. I wouldn't solder to those terminals, use spade lugs.
Why is there a zener diode in series with the coil, what is Vcc1?
 

MisterBill2

Joined Jan 23, 2018
19,394
Normally Vcc refers to Voltage, Collector Circuit, and is used with transistors. For circuits like this a better description would be "V+" .
Not trying to be critical but rather avoiding incorrect references that will be confusing in future conversations.
A serious caution is that all of the exposed metal parts of this relay are at the circuit potential and so if it is used for switching mains voltage there is a shock hazard in touching it. This caution is appropriate given the TS lack of familiarity with electrical devices.. Given the computer keyboard seen in the photos it is a puzzle. What variety of student at what level of school??
 

Phil-S

Joined Dec 4, 2015
238
Normally Vcc refers to Voltage, Collector Circuit, and is used with transistors. For circuits like this a better description would be "V+" .
Not trying to be critical but rather avoiding incorrect references that will be confusing in future conversations.
A serious caution is that all of the exposed metal parts of this relay are at the circuit potential and so if it is used for switching mains voltage there is a shock hazard in touching it. This caution is appropriate given the TS lack of familiarity with electrical devices.. Given the computer keyboard seen in the photos it is a puzzle. What variety of student at what level of school??
Exactly.
If the relay type and manufacturer is known, why not do a bit of legwork and see if the datasheet can answer the questions.

it looks like something hefty, so all the more reason to be cautious.
Given the 24V DC coil, it is something more likely found in a control panel.
A bit more information on the application or the assignment would help
 

MisterBill2

Joined Jan 23, 2018
19,394
Really, 24 volt relays are also found in lighting controls and commercial cleaning systems, as well as HVAC systems for even medium size building. My home heating/cooling system uses a few 24 volt relays, so do parts of the lighting system. So really, aside from control panels, 24 volt relays are in many other places. Of course, most do not look quite like that photo.
 

MaxHeadRoom

Joined Jul 18, 2013
28,824
Really, 24 volt relays are also found in lighting controls and commercial cleaning systems, as well as HVAC systems for even medium size building. My home heating/cooling system uses a few 24 volt relays, so do parts of the lighting system. So really, aside from control panels, 24 volt relays are in many other places. Of course, most do not look quite like that photo.
Many used in those applications are AC coil, the OP's is a DC version.
 
Top