# Relay test question **URL:** \ **Category:** General Electronics\ **Created:** [December 30, 2022, 4:20pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296 "2022-12-30T16:20:31Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![neketege88](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/neketege88/32/1099022_2.png) [@neketege88](https://forum.arduino.cc/u/neketege88)\ **Post date:** [December 30, 2022, 4:20pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/1 "2022-12-30T16:20:31Z")
I think this is a pretty stupid question, but I want someone to verify or correct me if I am wrong. I have a relay which I will picture. It is part of a 48v golf cart charger. The relay appears to have an AC voltage of 120VAC and a DC voltage of 28V. The power cord goes directly from the outlet to the relay. From the relay two wires go to a PCB and to a transformer. The wires going to the PCB I would assume should read around 28 VDC when the relay is connected. However, with a DVM I am getting about 55 VDC. I am assuming this means the relay is bad??? Is the PCB probably bad too because of the over voltage? Can I supply the PCB with an external source of 28 VDC to see if it will power up? Or, am I going about this the wrong way. Thanks! ![image](https://europe1.discourse-cdn.com/arduino/original/4X/6/c/d/6cd2e0869abba44a4c9374b05aaedd98c34ff6aa.jpeg) ---
**Author:** ![buckfast\_beekeeper](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@buckfast\_beekeeper](https://forum.arduino.cc/u/buckfast_beekeeper)\ **Post date:** [December 30, 2022, 4:37pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/2 "2022-12-30T16:37:02Z")
> [@neketege88](#): > > AC voltage of 120VAC and a DC voltage of 28V ????? The relays has a coil for 120VAC. Where comes the 28V from? Not from the relays. [Datasheet.](https://www.rlocman.ru/i/File/dat/Magnecraft/Power_General_Purpose/W9AS1A52_120.pdf). Where do you find the 28V? Use the multimeter in AC and measure the voltage. ---
**Author:** ![neketege88](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/neketege88/32/1099022_2.png) [@neketege88](https://forum.arduino.cc/u/neketege88)\ **Post date:** [December 30, 2022, 4:41pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/3 "2022-12-30T16:41:51Z")
I think I have confused myself… I’m pretty sure it says 28vdc on the relay I have (see zoomed pic). However maybe that is just the load that could go across the relay when energized? I’m confused as to what the relays purpose is here. Thanks!! ![image](https://europe1.discourse-cdn.com/arduino/original/4X/f/5/c/f5c180cee0dff47e19552e62ea96a6544305fb2e.jpeg) ---
**Author:** ![herbschwarz](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/herbschwarz/32/239314_2.png) [@herbschwarz](https://forum.arduino.cc/u/herbschwarz)\ **Post date:** [December 30, 2022, 4:44pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/4 "2022-12-30T16:44:11Z")
I see that it says coil: 120VAC. ---
**Author:** ![neketege88](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/neketege88/32/1099022_2.png) [@neketege88](https://forum.arduino.cc/u/neketege88)\ **Post date:** [December 30, 2022, 4:48pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/5 "2022-12-30T16:48:00Z")
> [@buckfast\_beekeeper](#): > > Use the multimeter in AC and measure the voltage. If I test the small wires coming out of the relay going to the PCB with the wires not plugged in to the PCB I get about 12-13 VAC. if I plug in the PCB and test I get around 65VAC. ![image](https://europe1.discourse-cdn.com/arduino/original/4X/e/5/b/e5b5e8b24ea4bde8374af8fb5fa5e02c29e2822c.jpeg) ---
**Author:** ![buckfast\_beekeeper](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@buckfast\_beekeeper](https://forum.arduino.cc/u/buckfast_beekeeper)\ **Post date:** [December 30, 2022, 4:48pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/6 "2022-12-30T16:48:54Z")
The type number is _ **W9AS1A52\_120** _ on the relays stay _ **COIL: 120VAC** _ what is correct according the datasheet. @28VDC you can use the relays until 30A. 30A @ 240V 50/60Hz. Minimum switching power 10mA @5V DC or 12VAC. All in the datasheet. ---
**Author:** ![neketege88](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/neketege88/32/1099022_2.png) [@neketege88](https://forum.arduino.cc/u/neketege88)\ **Post date:** [December 30, 2022, 4:51pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/7 "2022-12-30T16:51:52Z")
So, what voltage should I be getting when I measure with a DVM? I am getting the 120VAC from the wires that are connected directly to the power cord. How do I tell what I should be getting from the other two wires? Thanks. ---
**Author:** ![buckfast\_beekeeper](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@buckfast\_beekeeper](https://forum.arduino.cc/u/buckfast_beekeeper)\ **Post date:** [December 30, 2022, 4:52pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/8 "2022-12-30T16:52:59Z")
> [@neketege88](#): > > If I test the small wires coming out of th Draw how all is wired. I think you must have load to activate the relays. Have you a 120V AC lamp? Hang it on the wires and test. Be careful with 120V AC. ---
**Author:** ![neketege88](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/neketege88/32/1099022_2.png) [@neketege88](https://forum.arduino.cc/u/neketege88)\ **Post date:** [December 30, 2022, 4:57pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/9 "2022-12-30T16:57:38Z")
This is how it appears to me: ![image](https://europe1.discourse-cdn.com/arduino/original/4X/0/f/7/0f7d162aca74c53c9f04a7ec7a3296ca00d69e5e.jpeg) ---
**Author:** ![Paul\_KD7HB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_kd7hb/32/1127958_2.png) [@Paul\_KD7HB](https://forum.arduino.cc/u/Paul_KD7HB)\ **Post date:** [December 30, 2022, 5:02pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/10 "2022-12-30T17:02:25Z")
The relay is only there so you cannot drive away while charging the battery. ---
**Author:** ![buckfast\_beekeeper](https://avatars.discourse-cdn.com/v4/letter/b/74df32/32.png) [@buckfast\_beekeeper](https://forum.arduino.cc/u/buckfast_beekeeper)\ **Post date:** [December 30, 2022, 5:03pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/11 "2022-12-30T17:03:34Z")
For sure it isn't a normal use for relays and transformer. What is your normal network? 120V AC or 240V AC. ---
**Author:** ![neketege88](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/neketege88/32/1099022_2.png) [@neketege88](https://forum.arduino.cc/u/neketege88)\ **Post date:** [December 30, 2022, 5:11pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/12 "2022-12-30T17:11:02Z")
So, this is not how the PCB gets power? Does the PCB’s power come from the transformer output? Thanks! ---
**Author:** ![Paul\_KD7HB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_kd7hb/32/1127958_2.png) [@Paul\_KD7HB](https://forum.arduino.cc/u/Paul_KD7HB)\ **Post date:** [December 30, 2022, 5:28pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/13 "2022-12-30T17:28:16Z")
That would be how i would design such a system. The output of the charging system is always connected to the battery, just like any other charging system. The AC powered relay is just a safety measure. ---
**Author:** ![neketege88](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/neketege88/32/1099022_2.png) [@neketege88](https://forum.arduino.cc/u/neketege88)\ **Post date:** [December 30, 2022, 5:30pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/14 "2022-12-30T17:30:36Z")
> [@buckfast\_beekeeper](#): > > What is your normal network? 120V AC or 240V AC. 120vac ---
**Author:** ![neketege88](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/neketege88/32/1099022_2.png) [@neketege88](https://forum.arduino.cc/u/neketege88)\ **Post date:** [December 30, 2022, 5:41pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/15 "2022-12-30T17:41:04Z")
> [@Paul\_KD7HB](#): > > That would be how i would design such a system. The output of the charging system is always connected to the battery, just like any other charging system. The AC powered relay is just a safety measure. I’m not getting any power to the PCB. The only wires going in or out of the PCB are from that relay, from the transformer (which I have no power) and the other wires go to the receptacle that plugs in to the golf cart(obviously an output). So, is something supposed to tell the transformer to “turn on” or is it bad because I have ac power going in and nothing coming out? Thanks! ---
**Author:** ![neketege88](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/neketege88/32/1099022_2.png) [@neketege88](https://forum.arduino.cc/u/neketege88)\ **Post date:** [December 30, 2022, 5:55pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/16 "2022-12-30T17:55:31Z")
Ok, so I guess maybe I have been thinking about this wrong. Maybe the voltage from the golf cart batteries is what powers the PCB? ---
**Author:** ![Paul\_KD7HB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_kd7hb/32/1127958_2.png) [@Paul\_KD7HB](https://forum.arduino.cc/u/Paul_KD7HB)\ **Post date:** [December 30, 2022, 5:57pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/17 "2022-12-30T17:57:15Z")
A schematic of your system or even a block diagram showing and identifying all the interconnections is necessary for any additional help. OTherwise we are just guessing. ---
**Author:** ![neketege88](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/neketege88/32/1099022_2.png) [@neketege88](https://forum.arduino.cc/u/neketege88)\ **Post date:** [December 30, 2022, 6:01pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/18 "2022-12-30T18:01:11Z")
I just found this but I am guessing this is too basic? [https://www.buggiesgonewild.com/attachment.php?attachmentid=105064&d=1402665535](https://www.buggiesgonewild.com/attachment.php?attachmentid=105064&d=1402665535) The transformer has a mode number XFR034 14817R1-0503 Thanks again! ---
**Author:** ![Paul\_KD7HB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_kd7hb/32/1127958_2.png) [@Paul\_KD7HB](https://forum.arduino.cc/u/Paul_KD7HB)\ **Post date:** [December 30, 2022, 7:20pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/19 "2022-12-30T19:20:53Z")
What is important is what you have right there, not what someone on the web has similar to what you have. You need to draw boxes on paper of the major components you are concerned with. And then draw lines showing the interconnections. Label the connections. Possible boxes would be: 1, the relay you pictured 2. the transformer 3. the circuit board 4. the battery 5. the motor, ignoring any switch or rheostat to control the speed. Take a picture of your drawing and attach to a posting on this thread. ---
**Author:** ![johnwasser](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/johnwasser/32/214270_2.png) [@johnwasser](https://forum.arduino.cc/u/johnwasser)\ **Post date:** [December 30, 2022, 7:36pm UTC](https://forum.arduino.cc/t/relay-test-question/1071296/20 "2022-12-30T19:36:37Z")
See the white connector that seems like it should be connected to the PCB? The white wire is connected to the neutral side of the line voltage. The black wire, if it is connected to the white wire, will turn on the relay and provide line voltage to the transformer. Since the white connector is not connected, the transformer will not get power. [Next page](https://forum.arduino.cc/t/relay-test-question/1071296.md?page=2)