Hubbell Electric Heater Company J manual Construction Tank, Tank Connections, Heating Element

CONSTRUCTION

TANK

The storage tank is designed, manufactured, and stamped in accordance with ASME section VIII Division 1. The tank is constructed of type 304L stainless steel for maximum tank longevity and fabricated by all welded construction and is designed for a maximum allowable working pressure of 150 psi (225 psi TP).

TANK CONNECTIONS

The heater is supplied with separate connections for the cold/warm inlet and the hot water outlet. Water entering the warm water inlet and leaving through the hot water outlet is evenly circulated by means of a diffuser within the tank. A ¾-inch FNPT connection is provided for mounting a combination safety temperature and pressure relief valve. An overflow line should be utilized from the relief valve outlet to a floor drain. See drawing for locations and sizes.

HEATING ELEMENT

The water heater is supplied with an electric immersion heating element assembly(s), composed of copper sheathed elements that are fitted into a brass 1½-12UNF screw plug with 1-7/8” hex. Each assembly is threaded into the tank and sealed with an o-ring gasket. See drawing for voltage and power ratings.

MAGNETIC CONTACTOR

The definite purpose magnetic contactor(s) is a heavy-duty resistive load type. The contactor supplies power to the heating element(s) based on the resistive load (non-inductive) of the heater only when the relay on the control board is closed, thereby pulling in the contacts until the desired temperature is reached. At this point, the contacts will drop out, which in turn disconnects power from the elements. Units with two contactors will turn on and off in stages.

CONTROL BOARD AND DISPLAY The control board supplies all the necessary function for heater operation. These include control temperature, hi-limitcut-out, low water detection, and leak detection.

LOW VOLTAGE CONTROL TRANSFORMER

A control circuit transformer is supplied with all models rated greater than 240-volts. This component is used to step down the primary power supply (600, 480, 440, 415, or 380) to 208/240-volts for safety when working with control circuits.

POWER CIRCUIT BREAKERS

When required by code, a magnetic power circuit breaker is supplied for circuit overload protection. The circuit breaker can be reset in the event of a current overload.

OUTER SHELL, INSULATION, AND SUPPORTS

The tank is encapsulated in high efficiency polyurethane foam insulation meeting the requirements for UL 94 HF-1 rating. The protective shell is constructed of type 304 brushed stainless steel. NSF approved adjustable plastic legs are provided for support.

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