Sussman SSB 12-18 Installation, Operation And Maintenance Manual - page 7
Installation, Operation & Maintenance Manual
7
Pressure Controls, Operation and Testing
NOTE:
All boilers are provided with one high limit
pressure control and at least one operating pressure
control.
1. The high limit pressure control is equipped with a
manual reset feature. There is no subtractive
differential scale with this type of control
2. All pressure controls are equipped with an
adjusting screw, allowing for setting of desired
operational and high limit pressures. To reduce
pressure setting, turn adjusting screw in direction
that allows indicator to point to a lower pressure
setting on the scale. To increase pressure setting
turn adjusting screw in direction that allows
indicator to point to a higher pressure on the scale
NOTE
: It is recommended that the high limit control
be set 10psig above the desired normal operating
pressure.
3. Operating pressure controls, have a separate
differential scale. Differential indicates pressure
below the main operating maximum pressure, the
pressure control will re-set. The differential set
point is adjusted in the same manner by turning
the adjusting screw in the desired direction to
increase or decrease the differential pressure
value.
Pre-Operation Check (All Boilers)
LWCO/PUMP CONTROL OPERATION AND TESTING
1. All valves for incoming water supply are to be fully
opened. Main disconnect switch is to be in the
"on" position. Boiler main switch is to be in the
"on" position. Since boiler will be empty the pump
or solenoid will be energized allowing the boiler
to fill with water. Control will automatically fill
boiler to proper operating water level and the
pump/solenoid will be de-energized. Contactors
will then energize, applying voltage to the heating
elements.
2. Pump switch operation – at this point water should
be visible approximately half way up the sight
glass. Slowly open the drain valve located at the
bottom of the boiler. Water level in the sight glass
will begin to drop, allowing the low water cut
off/pump control to energize the feed water
system. Close valve for proper operation.
3. Low water cutout switch performance – open the
drain valve completely. Maintain this condition
until water level falls within the gauge glass
enough to cause the low water cutout switch to
de-energize the heating elements. All of the
contactors will be in a de-energized or open state
at this time. Close the drain valve, water feed system
will automatically refill the boiler and the contactors
will re-energize.
Boilers equipped with an auxiliary low water cut-off
control with a manual re-set button (required as
mandatory equipment is some states): once the correct
operating water level has been reached, it will be
necessary to depress the reset button in order for the
contactors to re-energize.
NOTE:
For boilers equipped with an automatic
blowdown system:
• FOR TEST 1
- the blowdown time clock must be in
the “run” mode before the boiler will automatically
fill.
• FOR TEST 2 AND 3
- in order for the drain valve to
open the blowdown clock must be in the “off” mode.
(See blowdown time clock insert) The automatic
blowdown indicator light will be on when the valve is
open. This light will remain on for the duration of the
blowdown cycle (a few seconds). It may be necessary
to cycle the time clock from the “run” to “off” mode
several times.
4. Operating pressure control check: Close steam
outlet valve [supplied by customer] and adjust
operating pressure control to 20psig and the
differential to 10psig. Set the high limit pressure
control to 30psig. Switch boiler on to allow steam
pressure to build-up. Pressure gauge reading will
increase and the operating pressure control will de-
energize the contactor(s) when the pressure gauge
indicates 20psig. Open steam outlet valve to bleed
off pressure. When the pressure gauge reading
decreases below 10psig (differential) the operating
pressure control will re-energize the contactor(s).
5. High limit pressure control check: FOR TEST
PURPOSES ONLY! Set the high limit pressure control
10psig lower than the operating pressure control.
Close the steam outlet valve and switch the boiler
on to allow boiler to build pressure. When the
pressure gauge indicates the pressure at which the
high limit pressure control is set, the high limit
pressure control re-set button will pop-up and the
control will de-energize the contactor(s). Open the
steam outlet valve to bleed off pressure. The
contactor(s) should not re-energize on pressure
drop. The contactor(s) should only re-energize when
the pressure has dropped and the high limit
pressure control reset button is depressed.