Fan control

[crashcow]

Hi,

We're installing some vent fans in building A and want to be able to control them manually from building B. The control requirements are simply on/off/reverse. The two buildings are about 1km apart. There is a fiber optic communication backbone between both buildings.

After some research, I am thinking of doing the following:
[ul]
[li]Use fan soft starters in Bldg A containing a module that supports MODBUS TCP. Through this fieldbus, it's possible to start and stop the motor, read out currents and frequency, achieve info about warnings, faults, etc.[/li]
[li]Use a desktop PC in bldg B running Wonderware HMI software, which will send MODBUS TCP commands to the softstarters[/li]
[li]Use switches to convert from Ethernet to fiber (bldg B), fiber to Ethernet (bldg A) and then route the signal to individual starters.[/li]
[li]Note: No PLC is used[/li]
[/ul]

My questions are:
[ol 1]
[li]Will this work?[/li]
[li]Are there other alternatives I should look at?[/li]
[li]Would I be able to remotely login to the desktop PC to monitor and control the fans from another location if needed?[/li]
[/ol]

Thanks,
Bill

 

[ScottyUK]

[ol 1]
[li]Yes, it can be made to work. Whether it meets applicable codes regarding emergency stops and so on is more open to question.[/li]
[li]You mentioned one option - a PLC and either an MMI or PC. You can get safety-qualified PLCs with redundancy if that is a requirement. Most BMS hardware is capable of this functionality too.[/li]
[li]Given network access, yes you could. Whether you would want to is a different question given the potential for security problems.[/li]
[/ol]

 

[crashcow]

Scotty - thanks for the quality answers.
1. We will have local disconnects/hand off autos at the fans for emergency stop
2. I was planning on using just a PC with Wonderware. For redundancy, we will have a spare PC.
3. Re: security, I will check with our IT dept about using an ACL, firewall and/or encryption. Thoughts welcome.

Bill