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_ , <br /> r <br /> '1 <br /> r � � � <br /> � <br /> . _ _ . <br /> ��u�� ��� ' SqURRED COMPRNY - <br /> INTER-OFFICE <br /> � •� �scoma F.O. ••°- Assembly Products Marketing - Peru 1 <br /> ......,.. g �, amnins •• K. W. Breher >••• April 14, 19B3 <br /> .�..... AUTOMRTIC TRANSFER SWITCHES `'" <br /> . �� � �,,���.�'" D <br /> Re: UL Labels �� Ap�; 2 6 �9g3 <br /> � / � � __ �:i i <br /> �� n r�T�,�r rn <br /> Brad: <br /> In respmse to your recent call conceming the lack of a UL label on a Class <br /> 8901 Type VO-5 Nutomatic Transfer Switch, I wish to outline the probable <br /> reasons why this particular unit did not have a Ul. lebel affixed to it. <br /> The Type VO-5 device is an automatic transfer switch which was built aro�md <br /> the now obsolete vertical action contactor. This particular unit is a <br /> 4 pole/4 pole device rated for 2D0 amperes. This particular design goes back <br /> into the 1960's or earlier. It was not until 1972 that Underwriters' <br /> Laboratories enacted the first standard for automatic transfer switches. <br /> When the UL Standard (UL 1008) went into effect, the Square � Company began a <br /> series of tests and design changes in order to assure that as many transfer <br /> switches as possible manufactured by the Square D Company would have the UL <br /> label affixed. This series of testing and design changes resulted in the <br /> "Series E" vertical action transfer switch. The changes which were undertaken <br /> under the Sei'ies E program were directed toward standardizing the product <br /> offering and providing the ability to provide various UL listed factory <br /> mnodifications on a fairly short delivery schedule. <br /> This should in no way reflect that the previous offering, which was not <br /> sub,jected to the UL listing program, was not,a quality product. It should be <br /> ' pointed out that all oF the components used in this previous product oi'fering <br /> were identical to those utilized under the Series E, UL listed program. <br /> I hope this clears up the question on why this parti�ular unit may not have a <br /> UL label affixed to it. If there are any further questions, please feel free <br /> to contact me in Peru. <br /> Best r ar s, <br /> ✓� �� <br /> ;I�j <br /> � �Cenneth W. reher <br /> L �:Fi �. . � J <br /> i09B/ko <br /> � Oc FVE:., . <br /> , . , ;, � . , <br /> L eo.n _ <br /> L <br /> J <br />