Troubleshooting - Honeywell Braukmann T100A Product Data

MV100 ELECTRIC CONTROLLERS T100, T200 THERMOSTATIC CONTROLLERS AND V100 RADIATOR VALVES
NOTES:
— While the T100 is satisfied, the V100P is closed and
the radiator remains airlocked. Thus, no steam can
enter the radiator. The airlocked condition remains
until the T100 calls for heat, at which point the
system operates as described in steps 1 through 6.
— An improperly cycled boiler causes either excessive
heating or lack of heat, depending on the system
time constant.
Bringing the Steam Pressure to Zero psig
To assure the proper operation of any single-pipe steam
system, ensure that the steam pressure is brought to zero at
some time during the off-cycle. One suggested procedure
follows:
1. Determine if steam is required using one of two
methods:
a. A thermostat in a representative zone controls the
valve or cycles the boiler.
b. A timing device cycles the boiler for varying
lengths of time in response to outdoor
temperature.
IMPORTANT
When cycling the boiler from a space thermostat in a
zone, do not apply a radiator valve to that radiator.
2. Turn off the steam and allow system pressure to drop to
zero. Do this using one of two methods:
a. Turn the boiler off and allow the total steam
pressure in the system to drop to zero.
IMPORTANT
Before applying controls to turn a boiler on and off,
check the manufacturer's recommendations.
b. In installations where turning the boiler off at the
end of each cycle is undesirable, install a control
valve (such as a Honeywell V5011 Valve) on the
boiler discharge line.

TROUBLESHOOTING

Refer to Table 6 for troubleshooting details.
Symptom
Not all sections Many radiators are oversized and not
of the radiator all sections heat to maintain the
are heating. desired temperature.
Underheating. Sensor in the wrong location.
T100A,M Controller mounted in a
vertical position above the hot pipe.
Excess capillary tubing coiled above
or too close to the heat source.
Flow through the valve is in the wrong
direction.
Inadequate system temperature or
pressure.
62-3048—1
Table 6. T100/V100 Troubleshooting.
Possible Cause
NOTE: Install the valve on the boiler side of the
condensation takeoff to ensure that the
condensation can return to the boiler.
3. Verify that the steam pressure has returned to zero.
Verification
Verification is necessary to prove that the pressure has
returned to zero. Simply turning off the boiler or shutting off
the steam supply does not ensure zero steam pressure. The
simplest way to check for zero pressure follows:
1. Install a strap-on Aquastat® Controller, such as the
Honeywell L6006C Aquastat Controller, on the
condensation return line (see Fig. 19).
2. Set the Aquastat Controller at about 150°F (66°C). With
the return line at or below this temperature, the water is
all condensation, and the pressure is functionally zero.
3. Wire the Aquastat Controller into the interrupting circuit
to ensure that steam flow cannot resume until the
condensation line is below the setpoint. The 150°F
(66°C) setpoint serves as a nominal starting point and
can require adjustment for individual steam systems.
MASTER ZONE
THERMOSTAT
1
L1
24
(HOT)
Vac
L2
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND
OVERLOAD PROTECTION AS REQUIRED.
Fig. 19. Holding circuit for use with L6006
when verifying zero psig steam pressure.
Solution
System is operating properly.
Change the sensor location or change the control type. See
Installation Instructions.
Mount the T100A,M horizontally, or switch controller to a
T100F.
Coil excess capillary tubing below or away from heat source.
Check the arrow on the valve body. It should be in the
direction of the flow. Change the valve direction or flow
direction.
Check boiler operating and limiting controls, circulating pump,
and isolating valves.
10
L6006C
LOW
VOLTAGE
RELAY
PRIMARY
CONTROL
M7536A
(continued)