03/19/2009
12
BI502
OPERATIONAL TIPS
Normal/Standby Switch
If this system does not have a standby operating (gas or oil) boiler, this switch must always be in
the “normal” position.
To activate standby boiler, simply position front panel switch to “standby”.
Monitor Lights, Front Panel
HI-LIMIT, red – this will
only
illuminate when the vessel hi-limit opens due to excessive high
water temperature. This hi-limit is self resetting.
PWR ON, green – basically this is illuminated at all times. It represents 24-volt power source,
good fuse, controller logic is operational, and a good outlet sensor. If the outlet sensor is
inoperative, incorrectly wired, or malfunctioning; this green monitor LED should be in the
blinking or pulsing mode (see page 11).
EL MODE, amber – when illuminated the system is in the electric mode. If it is not illuminated
the utility load control receiver is in the interrupt or on-peak mode. If there is an optional or
remote standby switch, the status of the standby switch is also monitored by this amber LED.
HEAT ON, red – indicates a remote switch closure (t-stat or zoning end switch) is closed between
terminals R and W.
Inside Controller Board
STAGES, red – these four LED’s indicate which electric element stages are on and active.
Manual Reset, Hi-Limit
At the top of the vessel there will be either two or three surface mount hi-limits preset at 205° F. There is
no light indicator associated with these safety hi-limits. Also these 205° F safety limits break the L2
current carrying 240-volt wire going to the elements. Reset involves locating a small shiny lever or metal
tab protruding on the side of the black safety limit base. This small tab is pressed inward approximately
1/8” to “snap in” the contacts.
Safety caution
– the wires and screws have 240-volt potential and can be dangerous. Turn off
circuit breakers before investigating or attempting to reset the 205° F safety limits.
Internal Fuse
The fuse on the controller board protects the transformer secondary, external items connected to “R”, and
the circuit board itself. Replace with 2-amp fast blow, AGC2 or equivalent.
Stat Heat Anticipator
- If it is a mechanical stat, verify heat anticipator has been set at Ø.2 (non-zone
system).
System Pressure
The side press/temp. gauge should be at approximately 10 to 16 PSI at room temperature water and
should not rise more than approximately 4 PSI at the operating or hot water temperature. If the pressure
change is more than approximately 4 PSI, the expansion tank is too small or there is a problem with the
expansion tank piping, expansion tank itself.
Cold slab, outdoor reset and temperature sensing prevent full boiler on
– by adding a
temporary
jumper between the lower W screw terminal and the upper left “E” tab, all temperature sensing functions
are bypassed and the control board will step in all the stages.
Caution:
This jumper shall not be a
permanent function, jumper needs to be removed after slab is approaching normal temperature.
