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Sub-clause 22.106 of standard IEC 603325-2-21:2002 states that, a closed water heater shall incorporate a thermal cut-out providing all-pole disconnection which operates independently from the thermostat. 5 b$ y l* [5 b- s4 d2 R1 T! @Can the thermal cut-out and thermostat control the same contactor, when a contactor is used or are two contactors needed, one controlled by the thermal cut-out and one controlled by the thermostat? - S- }! B' x+ dDecision:4 |" A' G& c( Q1 A1 o1 w& P; ~
Two contactors or relays must be used because the contactor or relay may not operate if one set of independent contacts welds closed. See also 19.14 in IEC 60335-1 Ed 4.2.. 5 D9 q4 h4 S1 `3 Y8 F1 f, X8 @ 5 K7 t4 E+ @! N8 d( @[attach]75706[/attach]2 v- _5 h+ ]7 g# I, _3 n
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