I'm building a simple circuit to control a 100W that takes 30-34V using a 30V LED power supply with constant current of 3.2A. I am controlling the switching of the LED with a Crydom DC60S5 connected to an Arduino Yun and the LED power supply with the following wiring:
Here is a photo of the actual wiring:
The problem is that when I plug in the power without even connecting the Arduino (nothing connected to terminals 3 and 4 on the relay, just as seen in the picture) the LED switches on. I've double checked that I have the DC60S5 relay, not the DC60S5-B which defaults to closed. If the circuit is unplugged and I do a continuity check with my multimeter across terminals 1 and 2 I don't get any beeping, and measured resistance is too high to register. If I put a 9V battery across the inputs the resistance drops to 60kOhm. This is confusing since 60kOhm is the AC impedance as stated in the data sheet, but I have the Crydom DC60S5 not the Crydom DC60SA5 which is the AC controlled model of this relay so I would have expected to get 1.5kOhm resistance as stated in the data sheet for DC control.
The relay doesn't seem broken, since I can still control it with a battery and measure it turning on/off. However without anything connected to the inputs it defaults to on which is not the expected behavior. Can anyone point me in the right direction as to what I might be doing wrong here?