G36FreezeProtectionStage1.py

"""
G36 2021

### Description

5.16.12.1.	If the supply air temperature drops below 4.4°C (40°F) for 5 minutes, send two (or more, as required to ensure that heating plant is active) heating hot-water plant requests, override the outdoor air damper to the minimum position, and modulate the heating coil to maintain a supply air temperature of at least 6°C (42°F). Disable this function when supply air temperature rises above 7°C (45°F) for 5 minutes.

### Verification logic

```python
if supply_air_temp < 4.4 (continuously 5 minutes) and outdoor_damper_command > outdoor_damper_minimum:
  fail
elif outdoor_damper_command > outdoor_damper_minimum and not (supply_air_temp > 7 (continuously 5 minutes)):
  fail
else:
  pass

if never (supply_air_temp < 4.4 (continuously 5 minutes)):
  untested
```

### Data requirements

- supply_air_temp: supply air temperature
- outdoor_damper_command: outdoor air damper
- outdoor_damper_minimum: outdoor air damper minimum position

"""

from constrain.checklib import RuleCheckBase


class G36FreezeProtectionStage1(RuleCheckBase):
    points = ["supply_air_temp", "outdoor_damper_command", "outdoor_damper_minimum"]

    def ts_verify_logic(self, t):
        if not t["freeze_status"]:
            return True
        if (t["sat_lowerthan_4.4_timer"] > 5) and (
            t["outdoor_damper_command"] > t["outdoor_damper_minimum"]
        ):
            return False
        elif (t["outdoor_damper_command"] > t["outdoor_damper_minimum"]) and (
            not (t["sat_higherthan_7_timer"] >= 5)
        ):
            return False
        else:
            return True

    def add_timers(self):
        lt4p4_timer_list = []
        ht7_timer_list = []
        freeze_status_list = []
        lt4p4_timer_start = None
        ht7_timer_start = None
        freeze_status = False
        for i, t in self.df.iterrows():
            if t["supply_air_temp"] < 4.4:
                if lt4p4_timer_start is None:
                    lt4p4_timer_start = i
                    lt4p4_timer_list.append(0)
                else:
                    time_delta = (i - lt4p4_timer_start).total_seconds() / 60
                    lt4p4_timer_list.append(time_delta)
                    if time_delta > 5:
                        freeze_status = True
            else:
                lt4p4_timer_start = None
                lt4p4_timer_list.append(0)

            if t["supply_air_temp"] > 7:
                if ht7_timer_start is None:
                    ht7_timer_start = i
                    ht7_timer_list.append(0)
                else:
                    time_delta = (i - ht7_timer_start).total_seconds() / 60
                    ht7_timer_list.append(time_delta)
                    if time_delta >= 5:
                        freeze_status = False
            else:
                ht7_timer_start = None
                ht7_timer_list.append(0)

            freeze_status_list.append(freeze_status)

        self.df["sat_lowerthan_4.4_timer"] = lt4p4_timer_list
        self.df["sat_higherthan_7_timer"] = ht7_timer_list
        self.df["freeze_status"] = freeze_status_list

    def verify(self):
        self.add_timers()
        self.result = self.df.apply(lambda t: self.ts_verify_logic(t), axis=1)

    def check_bool(self):
        if len(self.result[self.result == False] > 0):
            return False
        else:
            if self.df["sat_lowerthan_4.4_timer"].max() <= 5:
                return "Untested"
            else:
                return True