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67.5°F
L.H.ON
L.H.OF
H.H.ON
66.0°F
Fig. 7 — Heating Offsets
Demand Level Low Heat Off Offset (L.H.OF)
This is the heating set point offset above [the heating set point mi-
nus L.H.ON] at which point the Low Heat mode ends.
To enter into a LOW HEAT mode, if the controlling temperature
falls below [the heating set point minus L.H.ON], then HVAC
mode = LOW HEAT.
To enter into a HIGH HEAT mode, if the controlling temperature
falls below [the heating set point minus L.H.ON minus H.H.ON],
then HVAC mode = HIGH HEAT.
To get out of a LOW HEAT mode, the controlling temperature
must rise above [the heating set point minus L.H.ON plus
L.H.OF].
To get out of a HIGH HEAT mode, the controlling temperature
must rise above [the heating set point minus L.H.ON plus
L.H.OF/2].
The Run Status table in the local display allows the user to see the
exact trip points for both the heating and cooling modes without
doing the calculations.
Heat Trend Demand Level (H.T.LV)
This is the change in demand that must be seen within the time pe-
riod specified by H.T.TM in order to hold off a HIGH HEAT
mode regardless of demand. This is not applicable to VAV control
types (C.TYP=1 and 2) in the occupied period. This technique has
been referred to as "Comfort Trending." As long as a LOW HEAT
mode is making progress in warming the space, the control will
hold off on a HIGH HEAT mode. This is relevant for the space
sensor machine control types (C.TYP = 4) because the unit may
transition into the occupied mode and see an immediate and large
heating demand when the set points change.
Heat Trend Time (H.T.TM)
This is the time period upon which the heat trend demand level
(H.T.LV) operates and may work to hold off staging or a HIGH
HEAT mode. This is not applicable to VAV control types
(C.TYP=1 and 2) in the occupied period. See "Heat Trend De-
mand Level" section for more details.
HEAT MODE DIAGNOSTIC HELP
To quickly determine the current trip points for the low and high
heat modes, there is a menu in the local display which lets the user
quickly view the state of the system. This menu also contains the
cool trip points as well. See Table 44 at the local display under
Run Status
TRIP.
ITEM
HH.CF
HYDRONIC HEAT CONFIGS
HW.P
Hydronic Ctl.Prop. Gain
HW.I
Hydronic Ctl.Integ. Gain
HW.D
Hydronic Ctl.Derv. Gain
HW.TM
Hydronic PID Rate Config
ACT.C
HYDR.HEAT ACTUATOR CFGS.
SN.1
Hydronic Ht.Serial Num.1
SN.2
Hydronic Ht.Serial Num.2
SN.3
Hydronic Ht.Serial Num.3
SN.4
Hydronic Ht.Serial Num.4
C.A.LM
Hydr.Ht.Ctl.Ang.Lo Limit
Heating Set Point
68.0°F
L.H.OF/2
66.5°F
Table 45 — Hydronic Heat Configuration
EXPANSION
Table 44 — Mode Trip Helper Table
ITEM
EXPANSION
TRIP
MODE TRIP HELPER
UN.C.S
Unoccup. Cool Mode Start
UN.C.E
Unoccup. Cool Mode End
OC.C.S
Occupied Cool Mode Start
OC.C.E
Occupied Cool Mode End
TEMP
Ctl.Temp RAT,SPT or Zone
OC.H.E
Occupied Heat Mode End
OC.H.S
Occupied Heat Mode Start
UN.H.E
Unoccup. Heat Mode End
UN.H.S
Unoccup. Heat Mode Start
HVAC
the current HVAC MODE
The controlling temperature is "TEMP" and is in the middle of the
table for easy reference. Also, the "HVAC" mode can be viewed at
the bottom of the table.
TWO-STAGE GAS AND ELECTRIC HEAT CONTROL
(HT.CF = 1,2)
If the HVAC mode is LOW HEAT:
•
If electric heat is configured, then the control will request
the supply fan ON.
•
If gas heat is configured, then the IGC and IFO (IGC fan
output) controls the supply fan request.
•
The control will turn on Heat Relay 1 (HS1).
•
If evaporator discharge temperature is less than 50°F, then
the control will turn on Heat Relay 2 (HS2)*.
* The logic for this "low heat" override is that one stage of
heating will not be able to raise the temperature of the sup-
ply airstream sufficient to heat the space.
If the HVAC mode is HIGH HEAT:
•
If electric heat is configured, then the control will request
the supply fan ON.
•
If gas heat is configured, then the IGC and IFO output con-
trols the supply fan request.
•
The control will turn on Heat Relay 1 (HS1).
•
The control will turn on Heat Relay 2 (HS2).
HYDRONIC HEATING CONTROL (HT.CF = 4)
Hydronic heating in P Series units refers to a hot water coil con-
trolled by an actuator. This actuator is a communicating actuator
and may be field supplied. When Configuration
HT.CF=4, there is a thermistor array called Temperatures
AIR.T
CCT that is connected to the RXB, that serves as the
evaporator discharge temperature (EDT). The leaving-air tem-
perature (LAT) is assigned the thermistor that is normally assigned
to EDT and is located at the supply fan housing (Temperatures
AIR.T
SAT).
The configurations for hydronic heating are located at the local
displays under Configuration
RANGE
UNITS
0 to 1.5
HW_PGAIN
0 to 1.5
HW_IGAIN
0 to 1.5
HW_DGAIN
15 to 300
sec
HOTWPIDR
0 to 9999
HTCL_SN1
0 to 6
HTCL_SN2
0 to 9999
HTCL_SN3
0 to 254
HTCL_SN4
0 to 90
HTCLCALM
65
UNITS
CCN POINT
dF
UCCLSTRT
dF
UCCL_END
dF
OCCLSTRT
dF
OCCL_END
dF
CTRLTEMP
dF
OCHT_END
dF
OCHTSTRT
dF
UCHT_END
dF
UCHTSTRT
String
HEAT
HEAT
HH.CF. See Table 45.
CCN POINT
DEFAULT
1
1
1
90
0
0
0
0
85
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