PVI Industries PV500-25 - Manual (Page 9)

QUICKDRAW

Steam Heater
9
PV500-25 06/12
5.5 Steam Valves
Two position on-off electric valves are used. The valves will return to the closed position when power is off. This
feature will prevent an excessive temperature buildup in the event of a power failure. The valve manufacturer’s
operation and maintenance instructions ship with the unit. Refer to these instructions during start-up and file for
future referencing on maintenance.
CAUTION: Most valve problems are caused by dirt or trash in the steam line. This is most likely to occur during
installation. Teflon pipe tape, pipe joint compounds, metal particles and dirt will clog up strainers and orifices and
prevent valve seats from closing. Clean all pipe line strainers at start-up and check the valves again after a few
days operation as recommended maintenance by the valve manufacturer. Inspection of strainers and blowdown
piping should be part of the normal maintenance routine on this equipment.
5.6 Thermostat Settings – For Quickdraw instantaneous heaters only
The adjustable operating temperature control is located just above the front control panel cover. This control utilizes
a temperature sensing thermistor located in the control flange on top of the tank. Follow the safety instructions and
warnings included in this manual and with the product, when adjusting the set point of the operating temperature
control to deliver the desired water temperature.
The setpoint (SET) determines the desired stored water temperature in the tank and is factory set at approximately
120°F. If the tank temperature decreases below the set point a call for heat sequence is activated. The heating
sequence is turned off when the tank temperature again reaches the set point value.
To View The Setpoint
1. Press and quickly release the “SET” key. This will display the setpoint for 5 seconds.
To Change the Set Point
1. Press and hold the “SET” key for at least 2 seconds to enter the setpoint change mode.
2. The setpoint is displayed and the LEDs of the first and third digits blink.
3. To change the value, use the “UP” and “DOWN” keys.
4. The new value can be stored either by pressing the “SET” key (the control restores temperature display) or by
waiting the exit time-out to expire (15 seconds).
Key Combinations
1. TO UNLOCK THE KEYBOARD: Press and hold the “UP” + “DOWN” keys for 3 seconds. When the “PON”
flashing message is displayed, the keys are unlocked.
2. TO LOCK THE KEYBOARD: Press and hold the “UP”+ “DOWN” keys for 3 seconds. When the “POF” flashing
message is displayed, the keys are locked.
3. TO RETURN TO TEMPERATURE DISPLAY: Press the “SET” +”UP” keys.
6 START-UP PROCEDURE
1. After all the steam, condensate and water lines are installed and inspected, the steam supply source and the
condensate receiver should be checked for correct operation. Steam supply pressure to the heater must be
equal to or less than the supply pressure on the heater decal. A pressure reducing valve can be installed in the
supply line to meet this requirement.
2. Steam is directed to the heat exchanger through a header and steam control valves. The steam control valves
are normally closed, on-off, electric valves and solenoid-operated. Should an electrical power failure occur,
steam valves will close and stop steam flow to the unit.
3. When placing the unit into operation, open relief valve to purge air from top of tank and begin to fill the tank with
cold water. Check for plumbing leaks. Be sure to fill the tank completely before closing the relief valve.
CAUTION: Do not energize the heater or circulating pump until the tank is full of water. Serious damage may result.