Control system with coordinated equipment staging
A controller for heating, ventilation, or air conditioning (HVAC) equipment includes a communications interface configured to communicate with first HVAC equipment and second HVAC equipment and a processing circuit communicably coupled to the communications interface. The processing circuit is configured to detect a staging event for the first HVAC equipment occurring at a first time, obtain a delay time based on an estimated amount of time required to reach steady state after the staging event for the first HVAC equipment occurs at the first time, determine whether the delay time has elapsed since the staging event for the first HVAC equipment has occurred, and prevent the second HVAC equipment from staging in response to a determination that the delay time has not elapsed since the staging event for the first HVAC equipment has occurred.
1. A controller for use with a plurality of chillers, the controller comprising:
a processing circuit configured to:
select a first chiller for operation in response to a command;
determine whether a lag time has elapsed since the first chiller was started;
start a second chiller at least in part in response to a determination that the lag time has elapsed;
determine if more capacity is needed to satisfy a HVAC load;
determine whether another lag time has elapsed since the second chiller was started; and
start a third chiller in response to a determination that the another lag time has elapsed.
2. The controller of claim 1 , wherein:
the first chiller comprises a first pump; and
the second chiller comprises a second pump.
3. The controller of claim 1 , wherein counting of the lag time begins after the first chiller has achieved a first state.
4. The controller of claim 1 , wherein the processing circuit is configured to determine a staging event comprising at least one of activating or deactivating the first chiller, changing a load setpoint for the first chiller, and changing a capacity of first chiller.
5. The controller of claim 1 , wherein the processing circuit is configured to:
determine whether the first chiller is operating at steady state during a time period after the first chiller is started;
allow the second chiller to stage in response to determining that the first chiller is operating at the steady state over the lag time; and
prevent the second chiller from staging in response to determining that the first chiller is not operating at the steady state.
6. The controller of claim 1 , wherein the processing circuit is configured to:
initialize a lag timer for the lag time;
start the lag timer in response to starting the first chiller; and
determine whether the lag time has elapsed by determining whether the lag timer has expired.
7. A controller for equipment that includes at least first HVAC equipment and second HVAC equipment, the controller programmed to:
select first HVAC equipment for operation in response to a command;
determine whether a lag time has elapsed since the first HVAC equipment achieved a state associated with completion of staging the first HVAC equipment; and
start the second HVAC equipment at least in part in response to a determination that the lag time has elapsed.
8. The controller of claim 1 , wherein the lag time is a predetermined value stored in a memory.
9. The controller of claim 1 , wherein the processing circuit comprises a remote server.
10. A method for heating, ventilation, or air conditioning (HVAC) equipment comprising at least first HVAC equipment and second HVAC equipment, the method comprising:
detecting a staging event for the first HVAC equipment and starting the first HVAC equipment for operation in response to a command;
determine whether a lag time has elapsed since the first HVAC equipment was started; and
start a second first HVAC equipment at least in part in response to a determination that the lag time has elapsed detecting another staging event for third equipment occurring at a second time;
determining whether a second delay time has elapsed since the staging event for the second HVAC equipment has occurred; and
preventing third HVAC equipment from staging in response to a determination that the second delay time has not elapsed.
11. The method of claim 10 , wherein the first HVAC equipment comprises a first chiller circuit, and the second HVAC equipment comprises a second chiller circuit.
12. The method of claim 10 , wherein:
the first HVAC equipment comprises at least one of a first boiler, a first heater, a first pump, a first chiller, a first heat recovery chiller, a first cooling tower, or a first thermal energy storage tank; and
the second HVAC equipment comprises at least one of a second boiler, a second heater, a second pump, a second chiller, a second heat recovery chiller, a second cooling tower, or a second thermal energy storage tank.
13. The method of claim 10 , wherein the staging event comprises at least one of activating or deactivating the first HVAC equipment, changing a load setpoint for the first HVAC equipment, and changing a capacity of first HVAC equipment.
14. The method of claim 10 , further comprising:
determining whether the first HVAC equipment is operating at steady state during a time period after the staging event for the first HVAC equipment occurs; and
allowing the second HVAC equipment to stage in response to determining that the first HVAC equipment is operating at the steady state.
15. The method of claim 10 , further comprising:
initializing a lag timer;
starting the lag timer in response to detecting the staging event for the first HVAC equipment; and
determining whether a first delay time has elapsed by determining whether the lag time has expired.
16. The method of claim 10 , further comprising:
determining whether the first HVAC equipment is operating at steady state during a time period after the staging event for the first HVAC equipment occurs; and
preventing the second HVAC equipment from staging in response to determining that the first HVAC equipment is not operating at the steady state.
17. The controller of claim 7 , wherein the controller is programmed to:
determine if more capacity is needed to satisfy a HVAC load;
determine whether another lag time has elapsed since the second chiller was started achieved the state; and
start a third chiller in response to a determination that the another lag time has elapsed.
18. The controller of claim 7 , wherein the controller comprises a plurality of servers or computers at distributed locations.
19. The controller of claim 7 , wherein the state is a steady state and the controller is programmed to:
determine whether the first HVAC equipment is operating at the steady state during a time period after the staging the first HVAC equipment; and
prevent the second HVAC equipment from staging in response to determining that the first HVAC equipment is not operating at the steady state.