Hi Experts!
I'm trying to control a solenoid valve (don't have part number, but I've been told its a 24V DC 30 watt coil) with a PLC output card.
Supplier says to use a SSR interposing relay but customer prefers not to. I don't really have room in the cabinet either. Not fond of going against the equipment suppliers recommendation, but while they may not be the most sophisticated (no part numbers), they clearly have experience.
I'm looking for your comments on the feasibility and reliability of not using an interposing relay, and instead connecting the solenoid (via a fuse) to the output card directly. I'm thinking of using a 1756-OB16D output card. It is rated for 2A continuous (subject to maximum card of 8A) and 4A surge.
It also indicates its Pilot Duty (DC-13SQ) of 2A. Can someone enlighten me on what DC-13SQ means? (would my 30W coil require a rating of (30/24 = 1.25A?)
From my limited understanding, the greatest load is at initial energization, 4A at 24V is 96W. This should accommodate a 30 watt coil? I don't know if 30 watts is the maximum, or the continuous power consumption...
The other very important consideration is the inductive nature of the load, and its behavior on de energizing the solenoid. Luckily the OB16 card has the diode from RTN to OUT to provide a source for the current and limit the voltage.
Thanks for any feedback you give!
Cheers,
I'm trying to control a solenoid valve (don't have part number, but I've been told its a 24V DC 30 watt coil) with a PLC output card.
Supplier says to use a SSR interposing relay but customer prefers not to. I don't really have room in the cabinet either. Not fond of going against the equipment suppliers recommendation, but while they may not be the most sophisticated (no part numbers), they clearly have experience.
I'm looking for your comments on the feasibility and reliability of not using an interposing relay, and instead connecting the solenoid (via a fuse) to the output card directly. I'm thinking of using a 1756-OB16D output card. It is rated for 2A continuous (subject to maximum card of 8A) and 4A surge.
It also indicates its Pilot Duty (DC-13SQ) of 2A. Can someone enlighten me on what DC-13SQ means? (would my 30W coil require a rating of (30/24 = 1.25A?)
From my limited understanding, the greatest load is at initial energization, 4A at 24V is 96W. This should accommodate a 30 watt coil? I don't know if 30 watts is the maximum, or the continuous power consumption...
The other very important consideration is the inductive nature of the load, and its behavior on de energizing the solenoid. Luckily the OB16 card has the diode from RTN to OUT to provide a source for the current and limit the voltage.
Thanks for any feedback you give!
Cheers,