Hubbell Electric Heater Company J - Manual (Page 7)

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. Note that the J3 model element is a 1” NPS thread with a 1 ½” hex.
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-
limit cut-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, 380, or 277) 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 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. Plastic legs for the J3 and J4 models
are optional.
DIAL TEMPERATURE AND PRESSURE GAUGE
A combination temperature (30°-240° F / 0°-120°C) and pressure (0–200
psi / 0-1400 kPa) gauge with 3-inch dial is supplied with the unit for in-line
installation (shipped loose). The connection is ½” NPT with a 2” long
sensing probe. Dial temperature and pressure gauges for the J3 and J4
models are optional.
7