Thomas & Betts EPW dimensions Figure TYPICAL INSTALLATION, Control Fuse, 3.0START UP AND OPERATION

Figure 2

TYPICAL INSTALLATION

Control Fuse

*N.B.

WHERE THERMOSTAT BULB IS LOCATED OTHER THAN OUTLET, FLOW SWITCH IS RECOMMENDED.

2.7.5Optional expansion tank (for closed loop systems) is mounted in the outlet piping.

2.7.6A 1 1/2" NPT drain plug is fitted at the bottom of the heater. We recommend use of a drain valve to simplify clean-out of sludge which may accumulate in the vessel. Sludge build-up can cause heating element failure.

2.7.7For flow rates greater than 50 gpm, to reduce tank erosion, a bypass loop with regulating valve is recommended.

2.7.8Closed loop systems require an air bleed valve, preferably installed at the highest point in the piping loop.

3.0START UP AND OPERATION

3.1The EPW heater is designed to heat water in a non-hazardous environment. In some closed loop systems chemically stabilized ethylene glycol may be added to the water for freeze protection or to elevate the boiling point. If you are unsure as to suitability of glycol to your heating loop contact the factory.

3.2Check the electrical system for loose connections and tighten if required.

3.3After all piping is installed turn the thermostat to its lowest setting and operate the circulating pump for up to 1/2 hour to check for leaks and to remove air pockets. In closed loop systems use the air bleed valve to remove entrapped air. An air lock in the heater vessel could cause the heaters to run dry and fail prematurely.

3.4Set the thermostat to the desired temperature. The temperature rise through the unit will depend on the flow rate and the heater kilowatt (kw) rating.

For water: GPMUS =	6.83 kw
	Temp. Rise (°F)

Example: For a 30 kw heater and a 10°F temperature rise the flow required in U.S. gallons per minute is:

GPMUS =	(6.83)(30)	= 20.4
	10

Adjust the thermostat differential to give the desired cycling rate. It is best to use the maximum acceptable differential so as to minimize cycling and prolong component service life. However, if the system requires close control a narrow differential setting will be necessary.

3.5For systems using a by-pass loop, open the by-pass valve to reduce the load on the pump but not enough to cause the limit thermostat to open. For pool heating, the ideal by-

pass opening will result in water leaving the heater at not more than 90°F.