Thermon TraceNet TCM 18 - Manual (Page 82)

Rule Explanation
1. All RTD sensors programmed for ambient sensing shall be located in
ambients within the temperature range of -100F to +150F, or -73C to
+65C.
2. The RTD sensor for lowest numbered circuit within a specific TCM18
which has circuits programmed for ambient sensing becomes the sys-
tem control RTD. During normal scan the reading for this RTD will be
preceeded by the letter ‘a’ to indicate this is system ambient. Where
the operator has selected the 2 AMB option, there are two system am-
bient RTD readings (SysAmb1 and SysAmb 2).
3. If circuit(s) on the TCM18 are programmed for ambient sensing but
there is no RTD reading within the ambient range defined in Rule 1,
the corresponding SysAmb will be set to 1145 (an OPEN RTD).
4. Any circuit within a specific TCM18 which has either a single RTD or
a dual RTD combination and which is programmed to be an ambient
sensed shall use the readings from its own RTD input(s) as long as
the reading is within the defined ambient range specified in Rule 1.
Otherwise it will use the system ambient as defined in Rule 2.
5. Any circuit on the TCM18 which is programmed as a “2 APC” circuit
and where only one of its RTD sensor inputs is within the ambient
range specified in Rule 1 will use that RTD reading as one sensor
input and take the corresponding SysAmb1 or SysAmb2 for the other
system input.
As an example, suppose it is desired to have Circuits 2, 7, 9, 12, and 16 on a
TCM18 be ambient sensed as shown in the following list with all other circuits being
pipe sensed.
PN 50316_0514 78