Carrier WeatherExpert 48N2 Controls, Start-Up, Operation, Service, And Troubleshooting page 64

Configuring Hydronic Heat to Communicate Via Actuator
Serial Number
Every actuator used in the N Series control system has its own
unique serial number. The rooftop control uses this serial num-
ber to communicate with the actuator, with the exception of hy-
dronic and steam heat actuators. These serial numbers are pro-
grammed 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.
For the hydronic or steam heat actuators, these need to be field
programmed, as the actuators are field-installed accessories.
The hydronic or steam option uses either 2 or 4 actuators, de-
pending on the type of heat, unit tonnage, heat capacity, and
valves selected. Hydronic heat always has 2 actuators. Steam
heat always has 4 actuators, except on certain valve selections
on the 75-ton unit. Four individual numbers make up this serial
number and these can be programmed to match the serial num-
ber of the actuator in its Hydronic Heating Actuator Configs
group, ACT.C (SN.1.1, SN.1.2, SN.1.3, SN.1.4, SN.2.1, etc.).
See Fig. 10.
NOTE: The serial numbers for all 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.
MODULATING GAS HEAT CONTROL (HT.CF = 3 AND
HT.ST = 0, 1, 2, OR 3)
As an option, the units with gas heat can be equipped with
modulating gas heat controls that will provide infinite stages of
heat capacity. This is intended for tempering mode and temper-
ing economizer air when in a cooling mode and the dampers
are at minimum vent position. Tempering can also be used
during a pre-occupancy purge to prevent low-temperature air
from being delivered to the space. Tempering for staged gas,
modulating gas, and hydronic heat will be discussed in its own
section. This section will focus on heat mode control, which ul-
timately is relevant to tempering, minus the consideration of
the supply air heating control point.
The modulating gas and SCR electric heat configurations are
located at the local
 HEAT  SG.CF. See Table 37.
ITEM
SG.CF STAGED HEAT CONFIGS
HT.ST Staged Heat Type
CAP.M Max Cap Change per Cycle
M.R.DB
St.Ht DB min.dF/PID Rate
S.G.DB St.Heat Temp. Dead Band
RISE Heat Rise dF/sec Clamp
LAT.L LAT Limit Config
LIM.M Limit Switch Monitoring?
SW.H.T Limit Switch High Temp
SW.L.T
Limit Switch Low Temp
HT.P Heat Control Prop. Gain
HT.D Heat Control Derv. Gain
HT.TM Heat PID Rate Config
*Some configurations are model number dependent.
display under Configuration
Table 37 — Staged Heat Configuration
EXPANSION
ACTUATOR SERIAL NUMBER
00850 - 30063 - 084 -083
NOT SN.1 SN.2 SN.3 NOT
USED
Fig. 10 — Actuator Serial Number Configuration
SCR ELECTRIC HEAT CONTROL (HT.CF = 5, NO REQ.
SET HT.ST)
As an option, the units with electric heat can be equipped with
modulating SCR electric heater controls that will provide in-
finite stages of heat capacity. This is intended for tempering
mode and tempering economizer air when in a cooling mode
and the dampers are at minimum vent position. Tempering can
also be used during a pre-occupancy purge to prevent low tem-
perature air from being delivered to the space. Tempering for
modulating gas, hydronic, and SCR electric heat will be dis-
cussed 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.
Staged Heat Type (HT.ST)
This configuration instructs the control as to how many stages
and in what order they are staged. Setting HT.ST = 0, 1, 2, or 3
configures the unit for Modulating Gas Heat.
Max Cap Change per Cycle (CAP.M)
This configuration limits the maximum change in capacity per
PID run time cycle.
St.Ht DB Min.dF/PID Rate (M.R.DB)
This configuration is a deadband minimum temperature per
second rate. See capacity calculation logic on this page for
more details.
St.Heat Temp.Dead Band (S.G.DB)
This configuration is a deadband delta temperature. See capac-
ity calculation logic on this 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.
RANGE UNITS
0 to 3 HTSTGTYP
5 to 45 HTCAPMAX
0 to 5 HT_MR_DB
0 to 5 ^F HT_SG_DB
0.05 to 0.2 HTSGRISE
0 to 20 ^F HTLATLIM
No/Yes HTLIMMON
80 to 210 dF HT_LIMHI
80 to 210 dF HT_LIMLO
0 to 1.5 HT_PGAIN
0 to 1.5 HT_DGAIN
30 to 300 sec HTSGPIDR
64
SN.1 = 850
SN.2 = 3
SN.3 = 63
SN.4 = 83
SN.4
USED
CCN POINT DEFAULT
0*
45*
0.5
2
0.06
10
Yes
170*
160*
1
1
90*