Carrier WEATHERMASTER 48/50Z030-105 User Manual

Page 57

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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

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