Reference · built on requestOperator by FibricFacilities & comfort

Chiller Sequencing

Reviews chiller staging and lead-lag order against load, condenser water, weather, and grid prices, and proposes sequence changes.

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About

A chilled water plant is sequenced once at commissioning. Loads change, a chiller is retubed, a tower fan is replaced, and the lead-lag order and staging thresholds stay where they were set. Chiller Sequencing reads plant points from your building platform, chiller controller registers over Modbus TCP, the National Weather Service observation and hourly forecast for the site, and hourly demand and price for your balancing authority from the US Energy Information Administration.

It compares how the plant staged against the load it served and the weather it saw, and proposes changes: rotate the lead, move a stage threshold, start the plant earlier ahead of a forecast peak. Each is a proposal with the series attached. A person applies it. The operator never starts or stops a chiller.

This is a reference listing. It documents what Fibric would read from Chiller Sequencing and what it could propose, based on the vendor's published interfaces. Fibric builds it under a managed deployment when you request it; selecting it here installs nothing.

Inputs

  • Chilled water supply and return temperatures, flow, and each chiller's run state and stage, from your building platform or over BACnet/IP
  • Condenser water supply and return temperatures and tower fan status, so approach and lift can be compared across chillers
  • Run hours, fault codes, and the values each chiller controller exposes on the Modbus TCP registers you map
  • The configured lead-lag order and staging thresholds, read from the plant controller points that hold them
  • The latest NWS observation and hourly forecast for the site, with temperature, dewpoint, and relative humidity per period
  • Hourly demand for your balancing authority and the price series EIA publishes, so a start can be timed against the grid

Proposed actions

  • Target capability: propose rotating the lead-lag order when run hours are uneven or the lead chiller carries repeated faults
  • Target capability: propose moving a stage-up or stage-down threshold when the plant stages early or late against the load, with the series attached
  • Target capability: propose a plant start or pre-cool time ahead of a forecast peak in temperature or price, for your approval
  • Target capability: propose a review when condenser water approach widens on one chiller, with the readings that show it
  • Target capability: propose reverting an approved change when the following days do not show the expected staging

Proposed actions are target capabilities. Every action runs propose-first and needs a validated deployment and the appropriate permissions.

What you can build

  • Rotate the lead before it wears out

    Run hours read over Modbus TCP show one chiller leading every day while the other sits. Chiller Sequencing proposes the rotation, with both hour counts attached, and a person changes the order in the plant controller.

    With BACnet / IP, Modbus TCP

  • Pre-cool ahead of a priced peak

    The hourly forecast shows a hot afternoon and EIA shows a price peak in the same hours. The operator proposes an earlier start in Metasys so the building is cool before the peak.

    With Johnson Metasys, Weather & Severe Alerts, Grid Demand & Prices

  • Stage on the load you actually have

    Trend data from Niagara shows the second chiller staging on every mild day, then shedding within the hour. The operator proposes a higher stage-up threshold, with the days that show it.

    With Tridium Niagara, Modbus TCP, Weather & Severe Alerts

  • Spot the chiller that is fouling

    Condenser approach in Desigo CC widens on one chiller and not on its twin. The operator proposes a review with the series, before efficiency falls further.

    With Siemens Desigo CC

Requirements

  • A building platform connector with the plant's chilled water, condenser water, and chiller status points on its read allow-list
  • A Modbus TCP connector with a register map for each chiller controller
  • The site's coordinates for the NWS point forecast and nearest observation station
  • A free EIA API key and the balancing authority the site sits in
  • Write access on the sequence parameters, on the platform connector's allow-list, if you want changes applied after approval
Authentication
Chiller Sequencing holds no credentials. It reads through your building platform, Modbus TCP, NWS, and EIA connectors, and any proposed write goes through the building platform connector under its allow-list.

Limits

  • It proposes parameter changes. It does not start, stop, or stage a chiller, and it never writes to a chiller controller over Modbus.
  • Register maps differ by chiller maker and model. Values a controller does not expose cannot be read.
  • The NWS station may be some distance from the plant. Observed and site conditions can differ, and the operator says so on each proposal.
  • EIA demand and price series arrive as EIA publishes them. They inform planning; they are not a real-time signal.

Access and pricing

Reference listing. Fibric builds the operator under a managed deployment when you request it. Your quote covers the build, capabilities, usage, and support.

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Questions and answers

What do you approve before a sequence changes?
Each change to lead-lag order, a stage threshold, or a start time. The proposal shows the readings, the weather and price series used, the current setting, and the proposed one. Approve, adjust the value, or dismiss. Nothing is applied until you do.
What is recorded when a sequence changes?
A receipt per proposal: the load, temperature, weather, and price data that made the case, the setting before and after, who approved it, and how to return to the old sequence. Reverts leave their own receipt.
Will it ever start or stop a chiller?
No. It reads plant points and controller registers and proposes sequence parameters. Any write goes through the building platform connector to allow-listed points after approval. It never commands a chiller, a pump, or a tower fan directly.
Ask about Chiller Sequencing

Ask about the capabilities and requirements in this listing.

For project-specific requirements, contact Fibric.

This operator is developed, published, and supported by Fibric. Third-party names and logos identify the systems an integration connects to; they are the property of their respective owners, who are not affiliated with Fibric and do not sponsor or endorse this listing. Trademark policy