Armstrong The Brain DRV25 User Manual

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Armstrong International
221 Armstrong Blvd., Three Rivers, Michigan, 49093 - USA
armstronginternational.com/brain
Connectivity
The integral RS485 Serial Port (CN7 on the DRV25 PCBA) can be used to connect to either SAGE
®
or directly to
a Building Automation Systems (BAS) which operates on a Modbus RTU protocol.
SAGE
®
SAGE
®
is an optionally selected control module from Armstrong which enables an interface with Building Automation
Systems (BAS) which utilize Modbus, Bacnet™ or LonWorks™ protocols via the use of specic ProtoCessor cards.
SAGE BS
®
also has an ethernet port and operates as a web server for remote network access.
SAGE
®
includes remote hot water supply, cold / recirculation water supply, blended water outlet temperature outputs
and is supplied with a system graphic, memory card for data storage and web based software.
SAGE
®
includes terminals for additional installer supplied RTDs, pressure transducers and pulse type ow meters
and this data can be forwarded via the SAGE BS
®
interface.
A separate SAGE
®
specic Installation, Operation and Maintenance (IOM) Guide is available upon request.
Please consult factory or visit:
https://www.armstronginternational.com/sites/default/les/resources/les/503-EN.pdf
Modbus
DRV25 can be congured to communicate directly with a BAS which utilizes Modbus RTU.
When congured for Modbus the DRV25 becomes a Remote Terminal Unit (RTU).
When connected directly to a BAS using Modbus RTU, the DRV25 will be assigned a unique network address
which is congurable through the SAGE
®
mobile app.
A separate Modbus specic Installation, Operation and Maintenance (IOM) Guide is available upon request.
Please consult factory or visit:
www.armstronginternational.com/sites/default/les/resources/documents/IOM-776.pdf
System Performance
For e󰀨ective DRV25 performance, the DRV must be able to experience a minimum ow and a minimum temperature
di󰀨erential between its inlet and outlet supplies when the system is in zero demand.
Zero demand is dened as periods when there is no mixed water outlet usage on the system.
Pre-installation calculations should have already determined the system heat loss characteristics. For optimum
performance the DRV25 requires a minimum of 2°F (1°C) di󰀨erential between the setpoint (the outlet temperature)
and the thermometer which is installed on the system return line.
When there is no system draw-o󰀨, the DRV25 reverts to a zero demand. The recirculation temperature is continuously
monitored and adjusted appropriately by the DRV25. The circulating pump must operate continuously, the DRV25
requires a minimum ow of 2 gpm (8 lpm).
Pump Capacity
The circulating pump is only required to keep water gently moving around the system. The pump should be
sized and selected to overcome the system resistance (feet of head) at the minimum specied ow rate of
2 gpm (8 lpm) while also accounting for system heat loss.

Armstrong The Brain DRV25 Specifications

General

Brand	Armstrong
Model	The Brain DRV25
Category	Control Unit
Language	English