Raypak NH, 0133-4001 WH Controls General, Relief Valve, Electronic Ignition, Economaster Control

CONTROLS - GENERAL

RELIEF VALVE ELECTRONIC IGNITION

A new combination temperature and pressure (T&P) relief valve, complying with the Standard for Relief Valves and Automatic Gas Shut-Off Devices for Hot Water Supply Systems, ANSI Z21.22, must be installed in the opening provided on top of the storage tank at the time of installation. No valve is to be placed between the relief valve and the storage tank.

The pressure rating of the relief valve must not exceed the 160 maximum working pressure indicated on the water heater rating plate. The BTUH rating of the relief valve must not be less than the BTUH input of the heater.

Connect the outlet of the relief valve to a suitable open drain. The discharge line must pitch downward from the valve to allow complete draining (by gravity) of the relief valve and discharge line. The discharge line should be no smaller than the outlet of the valve. The end of the discharge line should not be threaded or concealed, and should be protected from freezing. No valve of any type, restriction or reducer coupling, should be installed in the discharge line. Local codes shall govern installation of the relief valve.

ECONOMASTER CONTROL

The Economaster II is an electronic device that allows the operator to set the desired time for the pump to run after the heater shuts off. The time is factory-set at 7 minutes and it can be re-adjusted in the field anywhere from 3 to 10 minutes.

In a conventional system, when the aquastat is satisfied, the main gas valve closes, but the pump continues operating. With the energy-conserving Economaster II, the heater pump is programmed to continue running for an optimum period of time in order to absorb the residual heat from the combustion cham- ber and use it in the system. The pump then shuts off until the next call for heat is received from the aquastat.

NOTE: Pump will come on when power is first applied to the heater.

The intermittent ignition device conserves energy by automatically extinguishing the pilot when desired temperature is reached. When additional heat is needed, the pilot re-ignites electrically, eliminating the fuel costs of maintaining a constant pilot. To assure safe operation, the gas valve cannot open until the pilot relights and is confirmed.

OPERATING CONTROLS

On models 514-1826, models with mechanical modulating controls have one or more Robertshaw Unitrol 7000 Series hydraulic snap on thermostatic combination gas valves. These valves have the pres- sure regulator and 24-volt operator built-in. The hy- draulic actuator will throttle the heater input to adjust the firing rate and meet the required load. This, in effect, prevents costly fuel consumption, as compared to an on-off cycling heater. The valve has a remote capillary bulb immersed in a well, at the header outlet, to main- tain a constant outlet water temperature. When mul- tiple valves are furnished, they can be staged to give greater flexibility of control. Standard factory setting is at position 5. Consult the dial setting tag attached to the control for your desired temperature. See chart below.

Fig# 9331 Fig # 9330.1

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