Solenoid Diaphragm Pump: Circuit Protection 1

[autonub]

I have a gamma/L pump from Prominent. I'm curious what the standard recommendations are for circuit protection when using these types of pumps (solenoid diaphragm pumps). I already have a circuit breaker in my design near the AC source. Would an overload relay be appropriate or unnecessary? I don't see any mention of inrush current in this particular pump's electrical datasheet. I'm not particularly experience with pumps so I'd value your insights. Thank you!

 

[btrueblood]

I don't think you can break those pumps by dead-heading them; they just stop pumping fluid. They might get hot, but I think (depending on the design) the temperature rise is self-limited by the increasing resistance of the coil; the manufacturer should be able to give guidance on that.

 

[micalbrch]

No, no, no, btrueblood! I cite from the operating manual:
– Always maintain the maximum permissible operating pressure of all hydraulic components
– Never allow the metering pump to run against a closed shut-off device.
– Install a relief valve.

autonub: Do you have the operating manual? If not:

http://www.prominent.de/Portaldata/...5_987604_BA_G_034_04-12_EN_gamma_L_EN_low.pdf

There is also a chapter about the electrical connection.

 

[autonub]

Thanks for the replies. Yes, I have seen and have read that Operating Instructions manual. To address the need for isolated relay contacts in parallel configurations (two of these sharing the same source), my intention is to use the relay outputs of a 1766-L32BXB PLC. The PLC has 6 onboard relay outputs rated for up to 15A at 120V AC. The pumps will be controlled via 4-20mA signals from the PLC logic, based on various discrete inputs from external components (sensors, switches, etc). In past projects I've worked on we used overload relays just before some mechanical contactors to protect the motors. This gamma/L is a different type of pump and is much smaller though, so I was hoping for a standard recommendation on how to protect these pump motors from overcurrent originating from other means (inrush startup, surges, shorts, etc) aside from just inductive kickback. The Operating Instructions manual didn't have quite enough information on this subject to put my mind as ease.

 

[bimr]

These pumps are relatively inexpensive and are typically connected to dedicated circuits from the circuit breaker panel. There is usually no overload relay. Maybe this brochure will help:

http://www.omega.com/manuals/manualpdf/M1756.pdf