Remote On-Off & Status for UNIFLAIR TDCV Units

[BillP]

Hello Everyone,

We are installing some TDCV Cooling Units in one of our Data Center Project where all these units will be controlled by a centralized Automation Controller, though during the configuration we are facing following issues and we would really appreciate if someone can guide us in resolving these issues.

1. Is there any built-in ModBus RTU Port available in TDCV Units or we must  use external Serial Cards with to integrate the units with our Automation Controller (supports RTU Connectivity).
2. Is there any Dry-Contact available in TDCV which can provide us status of the system means if the system is in working condition it provide us one state and whenever the system is off (due to any malfunctioning or alarm) it provides us a different state.
3. We want to control the units through a remote command and I believe DI-2,4 or 6 can be used for this purpose, however I just want to confirm if we have to apply 24VDC/AC to turn on the units through remote command or if the voltage should be applied to turn-off the running system. Moreover, if we want to use the system in Auto-Mode with Remote On/off enabled then do we have to enable Manual Override as well?

[BillP]

Hello Waleed.

The TDCV cooling unit will need a serial card to use modbus RTU. The Part number for the card is ACAC76123 (RS485). There is also a RS232 for modems ACAC76125.

There are two output dry contacts that can be configured to switch state when an alarm is on the unit.  C7 and C8 (J14 and J15) on the main board. The alarms will need to be set up under the settings and alarm relay selection section. This will not tell you if the unit is off but only if there is an alarm on the unit. You can choose which alarms change the state of the contact.

For the remote off, you are correct that DI-2,4 or 6 can be configured to turn off the unit. The unit will provide the 24 volts for the shutdown. Do not put an external 24 volt source on the inputs. This will fry the transformers in the unit. Connect a dry contact to the unit that is Normally Closed.  The unit is expecting to see the 24v at the input while the unit is running. A loss of the 24v will shut the unit down. Do not enable the manual override. All you will need to do is to go into the hardware settings and set up the input you connected to, to remote on/off.

Thank you

[BillP]

Hello,

Thanks a lot for your response.

As per my understanding of your below comment if the Digital input is set-up for remote on/off then by making it close the system will turn on and by disconnecting it system will be off, however it is not working I have set up one of the digital input and then short it by using a piece of cable but it didn't work or do we have to provide 24v from an internal  source available in the unit? 

I have also read the below faq from APC website according to which I think external has to be provided.

http://www.apc.com/us/en/faqs/FA173094/

I would really appreciate your support as this thing is delaying the complete project.

[BillP]

Hello,

Thanks a lot for your response, last night I gave configured it for CRAH and Chillers already.

Just another quick question, we have two external pumps installed for the chiller each pump is provided with its own VFD drive, as per our sequence whenever there is a failure in one pump the other pump will start within 5 seconds and within next 25 seconds it reaches to the required flow rate but within this transition time chiller is giving flow alarm and tripping please advise if there is any way to fix this.

[BillP]

Hello. Can you send me the model number of your chiller unit?

Thank you

[BillP]

Hello,

It is BREC1812.

[BillP · Accepted solution]

Hello.

Under the hardware configuration screen try setting the FS run delay to 30 seconds. This should allow enough time for the other pump to get up to speed before the flow alarm is triggered. If this does not work i would recommend calling into your local technical support to work through this issue further. 

Thank you