mr
.
steam
®
C U S E R I E S
Installation, Operating & Maintenance Manual
19
PRINCIPLES OF OPERATION
MR.STEAM CU Steambath Generators require two sources
of electrical supply – power voltage and control voltage.
Power voltage is usually 208, 240, or 480 volt, single or
three phase. Control voltage for generator suitable for
operation with these voltages is 120V, 1PH.
IMPORTANT:
In all cases, refer specifically to the boiler
data plate located on the outside of the boiler enclosure for
rated power and control voltages.
IMPORTANT:
See the generator nameplate for specific
electrical supply requirements for your steam generator. A
lighted ON/OFF switch activates the control circuit. MR.
STEAM CU Generators are equipped with automatic liquid
level/low water cut-off control. CU360 – CU1400 are
equipped with a dual probe type electronic control.
CU2000-CU4500 are equipped with float type MM150 con-
trol (Refer to wiring diagrams.) When there is no water in
the generator, the contactor is "OFF" and the water feed
solenoid valve is "ON". The unit will start filling with water.
When the water level has reached approximately halfway up
the gauge glass, the contactor(s) will be energized and, in
turn, energize the heating element(s). The water solenoid
will continue to feed water for a short time and then de-
energize. Steam will be available within a few minutes.
The generator has an electronic high water level cut-off con-
trol. If water level rises near the top of the pressure-sure
vessel, the contactor(s) and the water feed solenoid valve
will de-energize to “OFF”.
When steam pressure reaches the operating pressure con-
trol setting, the pressure control will de-energize the contac-
tor(s). Operating pressure control is factory set at
5
psig.
IMPORTANT:
It is recommended that the steam generator
not be operated higher than 5 PSIG.
Steam supply to the steambath is controlled by the Digital 1
Temperature Control System and the steam solenoid
valve(s). As the room temperature selected by the
owner/operator decreases below the set point, the Digital 1
Control will energize the steam solenoid valve(s) and allow
steam to enter the steam room. Once the set temperature
on the control is reached at the sensor, the control will de-
energize the steam valve, closing the valve and stopping
the flow of steam into the steam room.
The Digital 1 Kit is provided with Over Temperature
Control. Digital 1 monitors the room temperature inside
the commercial steambath. If the room temperature
exceeds the set point, the Digital 1 shuts off the power to
the CU Steambath Generator, shutting steam off. CU-HL
can also send a signal to an audible alarm (CU-Alarm sold
separately).
The pressure in the generator will decrease slightly as
steam leaves the generator and enters the steam room.
The pressure control will energize and de-energize the con-
tactor(s), maintaining the set pressure. As the water level
in the generator decreases, the liquid level control will
energize the water solenoid valve on and off and maintain
proper water level.
IMPORTANT:
Owners/operators should obtain a copy
and familiarize themselves with the latest edition of the
American College of Sports Medicine Health/Fitness
Faculty Standards and Guidelines, or a similar resource and
reference publication, and refer to those guidelines for the
proper and safe operation of a spa facility including steam
rooms.
The owner/operator has the responsibility to select a room
operating temperature meeting guideline requirements for
steam rooms.
Important Optional Equipment:
1. Optional Automatic Blowdown System (CU81600) has a
24-hour, 7-day timer that turns the steambath generator
ON and OFF. At the end of the "ON" cycle, the boiler is
automatically blown down, discharging daily accumula-
tion of minerals and salts which if not drained may affect
steam generator performance and operation.
2. An optional control circuit transformer provides control
circuit voltage from the power supply voltage. This
option is in lieu of the need for a separate control circuit.
3. An optional Auxiliary Manual Reset Low Water Cutoff
serves as a back up to the standard liquid level control
as required in some jurisdictions.
