Closed System Thermal Expansion; Electrical Connections - Bosch Tronic 3000T ES2.5 Installation Manual And Operating Instructions

3.3

Closed system thermal expansion

Periodic discharge of the temperature and pressure relief valve
or failure of the element gasket may be due to thermal
expansion in a closed water supply system. The water utility
supply meter may contain a checkvalve, backflow preventer or
water pressure reducing valve which will create a closed water
system.
During the heating cycle of the water heater, the water expands
causing pressure inside the water heater to increase. The
temperature and pressure relief valve may discharge hot water
under these conditions which results in a loss of energy and a
build-up of lime on the relief valve seat.
To prevent this from happening, there are two
recommendations:
1. Install a diaphragm-type expansion tank that is suitable for
potable water on the cold water supply line. A minimum 0.5
gallon expansion tank should be used.
Contact the local water supplier or plumbing inspector for
information on how to control this situation. Do not plug the
temperature and pressure relief valve.
1
Fig. 7
[1] Cable housing (internal to the unit)
[2] Wiring
[3] Protection ring for wiring.
[4] Additional grounding cable AWG16
(minimum length 152mm)
[5] Junction box left cover
[6] Nº3 self tapping screw for junction box covers fixing (with
lock washer or serrated head)
[7] Junction box right cover
[8] Nº1 self tapping screw for grounding
Tronic 3000T – 6 720 892 061 2019/02
3.4

Electrical connections

The ES8 model must be hard wired. As per the National Electric
Code the ES8 needs to be wired with 12 GA. wire to a 20 amp
branch circuit.
▶ Unscrew the junction box cover and remove it.
▶ Insert 12 AWG through conduit into junction box and
secure with conduit strain relief (not supplied).
▶ Connect the wires and screw on the cover of the junction
box.
▶ Make appropriate wiring connections to the water heater
per the National Electric Code.
The unit must be grounded with supplied grounding cable
inside junction box.
▶ Secure junction box cover once wiring connections have
been made.
When the ES8 is not within sight of the electrical circuit
breakers, a circuit breaker lockout or additional local means of
disconnection for all non grounded conductors must be
provided that is within sight of the appliance. [REF NEC
422.31].
2 3 4
(with lock washer or serrated head)
[9] Nº4 screws for junction box fixing
[10] Junction box
[11] Housing for junction box (in the plastic front cover)
Installation instructions
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