E.2
MASTERTRACE
Appendix E
Freeze Protection
(2) AMBIENT SENSING HEATER (msg. S3-12)
This message appears on MR100 only. Its selectable
choices are: None, HT 1-1, HT 2-1, HT 3-1, ..., HT 30-1,
and MR100.
If AMBIENT SENSING HEATER = None, the MR100
will be a standard MR100.
If AMBIENT SENSING HEATER = HT 1-1, Heater
1-1’s RTD is selected as the global ambient RTD. MR100
will read the global ambient RTD’s temperature
measurement from Heater 1-1 and broadcast this
measurement every 5 seconds.
If AMBIENT SENSING HEATER = HT 2-1, Heater
2-1’s RTD is selected as the global ambient RTD. MR100
will read the global ambient RTD’s temperature
measurement from Heater 2-1 and broadcast this
measurement every 5 seconds.
......
If AMBIENT SENSING HEATER = HT 30-1, Heater
30-1’s RTD is selected as the global ambient RTD. MR100
will read the global ambient RTD’s temperature
measurement from Heater 30-1 and broadcast this
measurement every 5 seconds.
If AMBIENT SENSING HEATER = MR100, MR100
will take the RTD connected to a 3rd party RTD transmit-
ter as the global ambient RTD. Terminal 913 & 914 on
MR100 are the connection points between MR100 and RTD
transmitter. The actual RTD is to be locally wired to RTD
transmitter as shown in Figure E.3. Since the RTD trans-
mitter is connected to MR100 via two 18 AWG wires, the
global ambient RTD can be located up to 7 km away from
the heat tracing panel. MR100 will read the global ambi-
ent RTD’s temperature measurement from the RTD trans-
mitter and broadcast this measurement every 5 seconds.
(3) AMBIENT RTD TEMP (msg. S3-13)
This measured message appears on MR100 only if the
AMBIENT SENSING HEATER is not selected as None.
It displays the global ambient RTD temperature measure-
ment from either HT 1-1, or HT2-1, ..., or HT30-1, or the
3rd party RTD transmitter connected to MR100.
Building Heat-Tracing Panel for Freeze Protection/
Process Control Mixed Application
Suppose a 20-point heat-tracing panel is to be built. The
module numbers of the two MS10 are assigned to 1 and 2 ,
respectively. The application requires that Heater 1-1, Heater
1-2, ..., Heater 1-10, Heater 2-1, ..., and Heater 2-8 are for
freeze protection application and Heater 1-1’s RTD or RTD
connected to RTD transmitter is the global ambient RTD.
Heater 2-9 and Heater 2-10 are for process control appli-
cation, which means they will use their own RTD sensors.
Using the special MS10/MR100 software, this panel can
be built in the following three configurations:
(1) Configuration 1 - Panel without MR100 & AMBI-
ENT SENSING HEATER = HT 1-1
This configuration is illustrated in Figure E.1. In this
configuration, two MS10 modules are linked togather
through a RS485 cable to form a network. Three RTDs are
equiped for temperature measurement. RTD1-1 is the glo-
bal ambient RTD for those 18 freeze protection heaters,
i.e., Heater 1-1, Heater 1-2, ..., Heater 1-10, Heater 2-1, ...,
and Heater 2-8. RTD2-9 and RTD2-10 are the sensors for
those 2 process control heaters, i.e, Heater 2-9 and Heater
2-10. This is a low cost panel configuration since there is
no MR100 mounted on the panel.
To meet the application requirements stated above, the
values of NUM OF AMB SENSE HTRS on the two MS10
modules have to be programmed by the hand-held ML100
like this: For module #1, set the value of NUM OF AMB
SENSE HTRS to Master 10. For module #2, set the value
of NUM OF AMB SENSE HTRS to Remote 8.
(2) Configuration 2 - Panel with MR100 & AMBIENT
SENSING HEATER = HT 1-1
This configuration is illustrated in Figure E.2. It differs
to the 1st configuration by the existence of MR100. User
can use the MR100 to program the two MS10 modules
and MR100 to meet the same application requirements as
the first configuration. Specifically, the values of NUM
OF AMB SENSE HTRS for the two MS10 modules and
the value of AMBIENT SENSING HEATER for MR100
have to be programmed like this: For module #1, set the
value of NUM OF AMB SENSE HTRS to 10. For mod-
ule #2, set the value of NUM OF AMB SENSE HTRS to
Remote 8. For MR100, set the value of AMBIENT SENS-
ING HEATER to HT 1-1.
(3) Configuration 3 - Panel with MR100 & AMBIENT
SENSING HEATER = MR100
This configuration is illustrated in Figure E.3. It differs
to the 2nd configuration by the existence of the 3rd party
RTD transmitter. User can should use MR100 to program
the two MS10 modules and MR100 to meet the applica-
tion requirements. Specifically, the values of NUM OF
AMB SENSE HTRS for the two MS10 modules and the
value of AMBIENT SENSING HEATER for MR100 have
to be programmed like this: For module #1, set the value
of NUM OF AMB SENSE HTRS to Remote 10. For mod-
ule #2, set the value of NUM OF AMB SENSE HTRS to
Remote 8. For MR100, set the value of AMBIENT SENS-
ING HEATER to MR100.
Important note:
For a freeze protection application, every module’s first
heater within the panel must be enabled in order for the
ambient temperature to be successfully transmitted and
received.
To Next Page
Loading...