Terminal Blocks - Component The devices covered under this category are incomplete in certain constructional features or restricted in performance capabilities and are intended for use as components of complete equipment submitted for investigation rather than for direct separate installation in the field. THE FINAL ACCEPTANCE OF THE COMPONENT IS DEPENDENT UPON ITS INSTALLATION AND USE IN COMPLETE EQUIPMENT SUBMITTED TO UNDERWRITERS LABORATORIES INC. GENERAL This category covers assemblies of wiring terminals and supporting blocks intended to provide a means for the connection of wiring. These terminal blocks may employ terminal connectors, wire-binding screws, quick-connect terminals and similar friction fit terminals, which are intended for factory-wiring and/or field-wiring connections. Protective conductor terminal blocks (PCTB) are intended for connecting protective earthing (grounding) conductors to supports, such as mounting rails and the like. A PCTB is marked with the international symbol for ground, "G,""GR,""GND,""Ground,""Grounding" or the like. In addition, the insulation of a partially insulated PCTB is colored green or green/yellow. USE The following performance levels include ratings for voltage, current, wire size and type, torque (if applicable), suitability for factory wiring only or field wiring, and use group in order to facilitate investigation of their use in end-product applications. The following statements explain the tabular information: Wire Range - The wire size or range of wire sizes for which a terminal block has been investigated. Unless clearly marked "Solid,""SOL,""Stranded" or "STR" for a given wire size, wire range or wire combination, conductors in the range 30-10 AWG are both solid and stranded, and 8 AWG and larger are for stranded wire only. Wire Type - The conductor material for which the terminal block has been investigated. "CU" represents copper wire only, "AL" represents aluminum wire only. "AL-CU" or "CU-AL" indicates use with aluminum and copper conductors, but not intermixed. The "7" or "9" associated with the wire type represents the temperature rating (75 or 90℃) of the wire connector. Factory and/or Field Wiring (FW) - These terminal blocks are rated for: Code 1, factory wiring only, or Code 2, both factory and field wiring. The suitability of the connections (including spacings between factory connectors) shall be determined in the end-use application. Unless noted with a "CA 4" in the last column, a terminal connector suitable for field wiring has been investigated to ANSI/UL 486A-486B, "Wire Connectors." When Code 1 and Code 2 terminals are intermixed on the same terminal block, both codes will be used with suitable indication for which terminal each code applies, i.e., 1/2. Torque (TQ) - The tightening torque(s) for a field-wiring pressure terminal connector other than a wire-binding screw, stud and nut type, or quick-connect type. If rated for factory wiring, this torque is only the manufacturer's recommended value. Voltage (V) - Terminal blocks have voltage ratings for which they have been found acceptable. A terminal block may have several voltage ratings that relate to the different use groups and spacing levels as tabulated under "Use Group." Current (A) - A maximum value of per-pole current for which the terminal block has been found acceptable. Short-circuit Current Rating (SCCR) - Terminal blocks are considered suitable for use on a circuit capable of delivering not more than the stated SCCR at the maximum voltage specified when protected by the max ampere and Class of over current protective device noted in the individual Recognitions. Short-circuit current ratings may be marked on the terminal block or on instructions provided with the terminal block. Short-circuit current ratings have been determined based on the terminal block's use within the minimum enclosure sizes as specified in Condition of Acceptability #6. Use Group (UG) - The type of end-use application for which the specified voltage and spacing level applies.