Marathon Special Products Double Row Terminal Blocks

Double Row Terminal Blocks are available in many line to line spacings. Open and closed back designs are available as shown in table below. Insulator bases are available in both phenolic and thermoplastic material. Modifications are also provided on most terminal blocks, including marking strips.

Ratings And Standards

The voltage ratings of terminal blocks are based upon the minimum spacing between electrically conductive parts line to line through air and over surface and line to ground through air and over surface.

Class A: Service, including deadfront switchboards, panel boards, service equipment and the like.
Class B: Commercial appliances including business equipment, electronic data processing equipment and the like.
Class C: Industrial, general

Spacing Requirements (in inches):

	Voltage	Thru Air	Over Surface
Class A	51-150 151-300 301-600	0.500 0.750 1.000	0.750 1.250 2.000
Class B	51-150 151-300 301-600	0.063 0.094 0.375	0.063 0.094 0.500
Class C	51-150 151-300 301-600	0.125 0.250 0.375	0.250 0.375 0.500

Series	Catalog Page	Amps	Voltage Rating ¹		Base Material	Max Wire Size	Screw Size	Inches L to L	Number of Lines	Features
Series	Catalog Page	Amps	Class B	Class C	Base Material	Max Wire Size	Screw Size	Inches L to L	Number of Lines	Features
100/670A GP	78	20	300+	N/A	Phenolic	#12	6-32	.375	1-36	Closed Back
200/671 GP	79	20	300+	N/A	Phenolic	#12	6-32	.437	1-30	Closed Back
300/672 GP	80	30	N/A	600	Phenolic	#10	8-32	.562	1-24	Closed Back
400	81	30	N/A	600	Phenolic	#10	10-32	.687	1-12	Closed Back
410¹	82	5	300+	N/A	Phenolic	#18	2-56	.250	1-23	Open Back
600¹	83	15	300	150	Phenolic	#12	5-40	.375	1-22	Open Back
600A¹	84	15	300	150	Phenolic	#12	6-32	.375	1-22	Open Back
800A¹	84	15	N/A	150	Phenolic	#12	6-32	.375	1-22	Open Back
601¹	85	20	300	300	Phenolic	#12	6-32	.437	1-23	Open Back
801¹	85	20	N/A	150	Phenolic	#12	6-32	.437	1-23	Open Back
602¹	86	30	300	300	Phenolic	#12	8-32	.562	1-26	Open Back
802¹	86	30	N/A	150	Phenolic	#12	8-32	.562	1-26	Open Back
603¹	87	50	600	600	Phenolic	#10	10-32	.687	1-12	Open Back
604¹	88	70	600	600	Phenolic	#4	12-32	.875	1-8	Open Back
605¹	89	90	600	600	Phenolic	#2	1/4-28	1.125	1-6	Open Back
621RZ	90	20	600	600	Thermoplastic	#12	6-32	.437	1-30	Closed Back/High Barrier
670ARZ	91	20	300+	150	Thermoplastic	#12	6-32	.375	1-30	Closed Back
671RZ	92	20	300+	N/A	Thermoplastic	#12	6-32	.437	1-30	Closed Back
672RZ	93	30	600	600	Thermoplastic	#10	8-32	.562	1-24	Closed Back

¹ Open back terminal blocks require an insulator strip to achieve voltage rating.