1. The Data Centers, LLC Wolf Technology Center 1 Campus
Dual & Redundant Distributed Controls
CCHP, HPC Data Center & Energy Storage
Bruce Myatt, PE
415–

2. Questions
Now that we’ve discussed the importance of having a control system, what kinds of control systems are available for HPC environments? And are the trade-offs?
Let’s discuss HPC Program Modes. What loads can be expected for commissioning, normal operation and even Linpack Benchmarking? What is the impact on controls in moving between these modes?

3. Data Center Control Systems Summary
Direct Digital Control (DDC)
Relatively low level of “critical” reliability
Typical application in commercial and light industrial HVAC and “comfort” applications
Pros
Low cost
Established / Familiar
Cons
Proprietary (protocols, structures are manufacturer-specific), low availability
Programmable Logic Controllers (PLC)
Higher level of “critical” redundancy
Typical application in industrial mfg. applications (Industrial HVAC, Chilled Water Plants, CHP)
Pros
Moderate cost
Easy configuration, “Open” development
Modular scalability & inter-operability;
Tier II, III and IV availability
Cons
Require skilled operations/maintenance staff
Moderately more expensive
Distributed Control Systems (DCS)
Most often used in high availability, high level of “critical” reliability
Typical applications (Power gen plants, highly analog applications, Oil and Gas, Nuclear, Mission Critical Facilities etc)
Pros
Highly available (system), reliable and robust – extremely fault tolerant, scalability Tier IV availability
Cons –
Require skilled/ knowledgeable maintenance staff, Higher capitalization costs
Direct Digital Control (DDC) Solutions
Somewhat low level of “critical” reliability
Typical application in commercial and light industrial HVAC and “comfort” applications
Pros – low cost
Cons – proprietary (protocols, structures are manufacturer-specific), low availability
Programmable Logic Controllers (PLC) solutions
Higher level of “critical” redundancy
Typical application in highly discrete industrial manufacturing applications (food production, packaging, etc); highly utilized in continuous process control applications such as utilities and “Balance of Plant” applications.
Pros – Moderate capitalization requirements, easy to configure, “open” industry-standard development environments, modular in scalability, inter-operability, scalability; tier II, III and IV
Cons – Still maturing in high-availability applications, require moderately skilled operations / maintenance staff
Distributed Control Systems (DCS) solutions
Most often used in high availability, high level of “critical” reliability
Typical applications (Power gen plants, highly analog applications, Oil and Gas, Nuclear, Life Safety, ESD, etc)
Pros – Highly available (system), reliable, and robust – extremely fault tolerant, scalability; tier IV
Cons – higher up front costs, require skilled / knowledgeable maintenance staff
SC’14 Critical Facilities Solutions, Inc.

4. Mechanical Plant Limitations & Performance
Open Cell Cooling Towers
Chillers w/Integral Free Cooling HXs
Looped Chilled Water Distribution at Roof Level
Condenser Water Pumps
Chilled Water Pumps
14”
16”
*Isolation Valves Will be Installed between Main Equipment on Roof to Segregate Loop
14”
14”
Racks with Rear Door HX
14” 6” 6”
Cross Tie Branches for Each Row of Racks 6” 6”
3-Way Control Valve at Each Rack to provide Individual Rack Temperature Control
14”
Isolation Valves between Equipment to Segregate Loop
Chiller Plant and HVAC Controls
Variable Speed Drive/ Pump and piping sizes 4