PVI Industries PV500-45U - Manual (Page 22)

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PV500-45U 06/12
10.3 High Water Temperature Limit Control
Appliances are equipped with adjustable limit and high limit controls to control the maximum discharge water
temperature. These controls are located inside the control cabinet and are accessed by removing the bottom cover.
The high limit control is optionally available as the manual reset type and may be reset by pressing the limit reset
button accessible through the control panel cover. Pressing the reset on the High Limit Control will not cause the
control to reset until the water temperature has dropped below the set point of the manual reset High Limit Control.
The Lower Limit is of the auto reset type and can be dial adjusted to operate just above the set point of the main
Operating Temperature Control.
10.4 Cathodic
Protection
PVI water heaters do not utilize cathodic protection. However, in hot water systems utilizing cathodic protection,
hydrogen gas can be produced when the hot water system has not been used for a long period of time (generally
two weeks or more). Hydrogen gas is extremely flammable. To prevent the possibility of injury under these
conditions, one of the hot water system faucets should be opened for several minutes before using any electrical
device connected to the hot water system. If hydrogen is present, there will be an unusual sound such as air
escaping through the pipe as the hot water begins to flow. Do not smoke, have open flames or turn electrical
switches on or off near the faucet at the time it is open.
10.5 Electronic Low Water Cut-Off (Optional)
When the water level is above the electrode position in the tank, the reset pushbutton will energize the control (LED
will be lit). The control remains energized until the water level recedes below the electrode position (LED will not be
lit). Unless otherwise specified, there is a three-second time delay on decreasing level. Water level must be below
tank probe location for full three seconds before control de-energizes.