All OCSTs shall meet the requirements of Section 110.2(c). Thermostats for heat pumps shall also meet the requirements of Section 110.2(b).
OCSTs shall include communication capabilities enabled through either
(a) At least one expansion port which will allow for the installation of a removable module containing a radio or physical connection port to enable communication; or
(b) Onboard communication device(s)
The OCST communications capabilities shall enable Demand Responsive Control through receipt of Demand Response Signals or price signals. After OCST communication is enabled and the occupant has enrolled in a Demand Response program or subscribed to receive demand response or pricing related messages or information updates, the OCST shall be capable of both receiving and responding to Demand Response Signals. The OCST with communications enabled recognizes two basic system event modes: price response and Demand Response Periods. Both basic system event modes can be overridden by the occupant.
JA5.2.3.1 Price Signals
Price signals allow the utility or another entity selected by the occupant to send a signal or message to the occupant’s OCST to provide pricing information to the occupant and initiate Demand Responsive Control for the Demand Response Period utilizing a Demand Response Signal.
Price signal attributes and requirements shall be specified within the messaging protocol utilized by the utility or other entity selected by the occupant.
JA5.2.3.2 Demand Response Periods
This event class allows the utility or another entity selected by the occupant to initiate Demand Responsive Control for the Demand Response Period utilizing a Demand Response Signal.
Demand Response Signal attributes and requirements shall be specified within the messaging protocol utilized by the utility or other entity selected by the occupant.
If a price signal or Demand Response Signal is received and validated, but conflicts with a prior message, the newer message shall supersede the previous message and any continuing action for the prior message is automatically terminated by the OCST (unless the subsequent message attempts to initiate an action that has been disapproved by the occupant).
Event response, unless overridden by the occupant or modified by an energy management control system or service, may be triggered by price signals or Demand Response Signals. The OCST shall provide one set of event responses for price signals and one set of event responses for Demand Response Signals. The responses may be common for both types of events.
OCSTs, with communications enabled, shall be capable of receiving and automatically responding to the Demand Response Signals as follows:
(a) A Demand Response Signal shall trigger the OCST to adjust the thermostat setpoint by either the default number of degrees or the number of degrees established by the occupant.
(b) When a price signal indicates a price in excess of a price threshold established by the occupant, the OCST shall adjust the thermostat setpoint by either the default number of degrees or the number of degrees established by the occupant.
(c) In response to price signals or Demand Response signals, the OCST shall default to an event response that initiates setpoint offsets of +4°F for cooling and -4°F for heating relative to the current setpoint.
(d) The OCST shall have the capability to allow occupants or their representative to modify the default event response with occupant defined event responses for cooling and heating relative to the current setpoint in response to price signals or Demand Response Signals.
(e) Override Function: Occupants shall be able to change the event responses and thermostat settings or setpoints at any time, including during price events or Demand Response Periods.
(f) The Demand Response Signal shall start the Demand Response Period either immediately or at a specific start time as specified in the event signal and continue for the Demand Response Period specified in the Demand Response Signal or until the occupant overrides the event setpoint.
(g) The thermostat’s price response shall start either immediately or at a specific start time as specified in the pricing signal and continue for the duration specified in the pricing signal or until the occupant overrides the event setpoint.
(h) The OCST shall have the capability to allow occupants to define setpoints for cooling and heating in response to price signals or Demand Response signals as an alternative to the default event response.
(i) At the end of a price event or Demand Response Period, the thermostat setpoint shall be set to the setpoint that is programmed for the point in time that the event ends or to the manually established setpoint that existed just prior to the Demand Response Period.
Unless the messaging protocol contains randomization or restoration delay logic, OCSTs shall provide a mechanism, such as a randomized delay, to prevent all of the OCSTs within a demand-response area from ending the demand-response event at the same time. This mechanism can be implemented within the control logic of the OCST, within the control logic of the demand-response signaling system, or within the control logic of the communication network between the OCST and the demand-response signaling system. The display of the thermostat shall accurately indicate the end of the event, accounting for any delays or advances provided by this mechanism. The specific maximum restoration delay for restoration after a Demand Response Period shall be 30 minutes or alternatively can be defined within the Demand Response Signal for that event.