57
Table 45 — Hydronic Heat Configuration
Hydronic Heating Control Proportional Gain (HW.P) — This
configuration is the proportional term for the PID which runs in
the HVAC mode LOW HEAT.
Hydronic Heating Control Integral Gain (HW.I) — This
configuration is the integral term for the PID which runs in the
HVAC mode LOW HEAT.
Hydronic Heating Control Derivative Gain (HW.D) — This
configuration is the derivative term for the PID which runs in
the HVAC mode LOW HEAT.
Hydronic Heating Control Run Time Rate (HW.TM) —
This configuration is the PID run time rate which runs in the
HVAC mode LOW HEAT.
Hydronic Heating Logic
If the HVAC mode is LOW HEAT:
• The control will command the supply fan on
• The control will modulate the hot water coil actuator to
the heating control point (Run Status
→
VIEW
→
HT.C.P). The heating control point for hydronic heat is
the heating supply air set point (Setpoints
→
SA.HT).
If the HVAC mode is HIGH HEAT:
• The control will command the supply fan on
• The control will command the hot water coil actuator to
100%
Hydronic Heating PID Process — If the HVAC mode is
LOW HEAT, then the hydronic heating actuator will modulate
to the heating control point (Run Status
→
VIEW
→
HT.C.P).
Control is performed with a generic PID loop where:
Error = Heating Control Point (HT.C.P) – Leaving Air Tem-
perature (LAT)
The PID terms are calculated as follows:
P = K * HW.P * error
I = K * HW.I * error + “I” last time through
D = K * HW.D * (error – error last time through)
Where K = HW.TM/60 to normalize the effect of changing the
run time rate.
NOTE: The PID values should be not be modified without
approval from Carrier.
Freeze Status Switch Logic (Inputs
→
GEN.I
→
FRZ.S) — If
the freezestat input (FRZ) alarms, indicating that the coil is
freezing, normal heat control is overridden and the following
actions will be taken:
1. Command the hot water coil actuator to 100%.
2. Command the economizer damper to 0%.
3. Command the supply fan on.
Configuring Hydronic Heat to Communicate Via Actuator
Serial Number — Every actuator used in the Z Series control
system has its own unique serial number. The rooftop control
uses this serial number to communicate with the actuator over
the local equipment network (LEN). These serial numbers are
programmed at the factory and should not need changing.
Should field replacement of an actuator become necessary, it
will be required to configure the serial numbers of the new
actuator. Five individual numbers make up this serial number
and these can be programmed to match the serial number of the
actuator in its Hydronic Heating Actuator Configs group,
ACT.C (SN.1, SN.2, SN.3, SN.4, SN.5).
NOTE: The serial numbers for all LEN actuators can be found
inside the control doors of the unit as well as on the actuator
itself. If an actuator is replaced in the field, it is a good idea to
remove the additional peel off serial number sticker on the
actuator and cover up the old one inside the control doors.
STAGED GAS HEATING CONTROL (HT.CF = 3) — As
an option, the units with gas heat can be equipped with staged
gas heat controls that will provide from 5 to 11 stages of heat
capacity. This is intended for tempering mode and tempering
economizer air when in a cooling mode and the dampers
are fully closed. Tempering can also be used during a pre-
occupancy purge to prevent low temperature air from being
delivered to the space. Tempering for both staged gas and
hydronic heat will be discussed in its own section. This section
will focus on heat mode control, which ultimately is relevant to
tempering, minus the consideration of the supply air heating
control point.
The staged gas configurations are located at the local
display under Configuration
→
HEAT
→
SG.CF. See Table 46.
Staged Gas Heat Type (HT.ST) — This configuration in-
structs the control how many stages and in what order are they
staged.
Max Cap Change per Cycle (CAP.M) — This configura-
tion limits the maximum change in capacity per PID run time
cycle.
S.Gas DB Min.dF/PID Rate (M.R.DB) — This configuration
is a deadband minimum temperature per second rate. See
capacity calculation logic on next page for more details.
St.Gas Temp.Dead Band (S.G.DB) — This configuration is a
deadband delta temperature. See capacity calculation logic on
next page for more details.
Heat Rise in dF/Sec Clamp (RISE) — This configuration
clamps heat staging up when the leaving-air temperature is
rising too fast.
LAT Limit Config (LAT.L) — This configuration senses
when leaving air temperature is outside a delta temperature
band around set point and allows staging to react quicker.
Limit Switch Monitoring? (LIM.M) — This configuration
allows the operation of the limit switch monitoring routine.
This is always enabled for Z Series as a limit switch tempera-
ture sensor is always present for staged gas operation.
Limit Switch High Temp (SW.H.T) — This configuration is
the temperature limit above which stages of heat will be shed.
Limit Switch Low Temp (SW.L.T) — This configuration is
the temperature limit above which no additional stages of heat
will be allowed.
Heat Control Prop. Gain (HT.P) — This configuration is the
proportional term for the PID which runs in the HVAC mode
LOW HEAT.
ITEM EXPANSION RANGE UNITS CCN POINT DEFAULT
HH.CF HYDRONIC HEAT CONFIGS
HW.P Hydronic Ctl.Prop. Gain 0 - 1.5 HW_PGAIN 1
HW.I Hydronic Ctl.Integ. Gain 0 - 1.5 HW_IGAIN 1
HW.D Hydronic Ctl.Derv. Gain 0 - 1.5 HW_DGAIN 1
HW.TM Hydronic PID Rate Config 15 - 300 sec HOTWPIDR 90
ACT.C HYDR.HEAT ACTUATOR CFGS.
SN.1 Hydronic Ht.Serial Num.1 0 - 255 HTCL_SN1 0
SN.2 Hydronic Ht.Serial Num.2 0 - 255 HTCL_SN2 0
SN.3 Hydronic Ht.Serial Num.3 0 - 255 HTCL_SN3 0
SN.4 Hydronic Ht.Serial Num.4 0 - 255 HTCL_SN4 0
SN.5 Hydronic Ht.Serial Num.5 0 - 255 HTCL_SN5 0
C.A.LM Hydr.Ht.Ctl.Ang.Lo Limit 0-90 HTCLCALM 85