Siemens UM344-2 user manual Thermocouple And Extension Grade Wire Characteristics

INSTALLATION UM344-2

Standard ANSI color coding is used on insulated thermocouple or extension grade wire when the insulation permits. Some insulations will use a colored tracer to indicate the lead polarity. Refer to Table 4.2 for color code information and bare wire characteristics for identifying non-color coded wires.

When connecting solid thermocouple extension wire, wire insulation should butt against the head of the screw. The conductor should not be visible.

TABLE 4.2 Thermocouple And Extension Grade Wire Characteristics

ANSI TYPE	POSITIVE LEAD		NEGATIVE LEAD		BARE WIRE
T/C	METAL	COLOR	METAL	COLOR	CHARACTERISTICS
T	Copper	Blue	Constantan	Red	Copper - yellow
					Constantan - silver
J	Iron	White	Constantan	Red	Iron - magnetic
					Constantan - non-
					magnetic
E	Chromel	Purple	Constantan	Red	Chromel - shiny metal
					Constantan - dull metal
K	Chromel	Yellow	Alumel	Red	Chromel - non-magnetic
					Alumel - magnetic
S	Platinum & 10%	Black	Pure Platinum	Red	---
	Rhodium
R	Platinum & 13%	Black	Pure Platinum	Red	---
	Rhodium
B	Platinum & 30%	Gray	Platinum with 0.6%	Red	---
	Rhodium		Rhodium

3)Ohms-to-Milliampere Conversion - connect the OHM (+), OHM (-), and OHM I leads as shown in Figure 4-13 detail E, Ohms Input.

4)Millivolt-to-Milliampere Conversion - Connect the mV (+) and mV (-) leads as shown in Figure 4- 13 detail F, mV Input.

Inspect each connection for strands of wire that could short to an adjacent terminal, for connection to correct terminal, and for tightness of terminal screw.

Be certain that the shield braid is insulated from all terminals and the metal terminal enclosure.

6.Reinstall enclosure cap. Tighten cap to compress the internal O-ring.

IMPORTANT

Be certain that enclosure threads are coated with an anti-seize compound and that the cap seal (O-ring) is in place before installing a cap. A typical compound is Never-Seez by Emhart Bostik.

4-34 September 1995