
™
TOXALERT
LEAD/LAG CONTROLLERS MODEL PSP & BSP
Pump/Boiler
GENERAL DESCRIPTION:
Toxalert has two basic lead/lag controller types. One designed for dual circulating pumps and the
other to automatically sequence boilers when they are to be controlled in a lead/standby sequence.
ON-OFF AUTO:
Both controller types feature an internal ON-OFF-AUTO switch mounted on the printed circuit board
that operates the controlled equipment. In the “AUTO” position the controller automatically operates
the controlled equipment via a SPST outdoor air thermostat. In the “ON” position the equipment is
positively turned ON, and positively turned off in the “OFF” position. The ON-OFF-AUTO switch
function can be remotely controlled by installing a three position switch remote from the Lead/Lag
controller (See technical description).
LEAD/LAG:
The LEAD/LAG switch is also mounted on the printed circuit board and is designed to choose the lead
equipment. With the switch in the R-1 (relay #1) position, pump #1 or boiler #1 is in the LEAD
position and equipment operated by relay 2 is automatically in the lag or standby position. With the
switch in the R-2 position the equipment (pump or boiler) operated by relay #2 is in the lead position,
and equipment connected to R-1 automatically becomes the lag or standby equipment. The
LEAD/LAG switch function may also be controlled remotely by simply installing a remote SPST
switch. (See technical description.)
r Panel
(CM) Custom Mount Models
PSP-10CM shown
TOXALERT INTERNATIONAL, Inc., PO Box 159, Mound, MN. 55364 PHONE: (952) 472-4541 • FAX: (952) 472-4960
www.toxalert.com

FEATURES:
LOW VOLTAGE CONTROL CIRCUITRY
•
Flow
Switch and outside air thermostat operation
(24VAC).
LIGHT EMITTING DIODES
•
status indication, long life, maintenance free
operation.
1) POWER ON – (Green)
2) FLOW NORMAL – (Green)
3) FAILURE – (Red)
SPDT CONTACTS FOR REMOTE
•
ALARM ANNUNCIATION
ALL MODELS
•
VAC
will operate on 120, 208 or 240
(LED’s) for
STANDARD MODELS:
ON-OFF-AUTO OPERATION:
•
AUTO – requires outdoor air thermostat to activate
sequencer circuits.
OFF – positive OFF of system.
ON – positive On of system, bypasses the outdoor
air thermostat.
REMOTE CONTROL:
•
Lead/Lag switch and ON-OFF-AUTO switch
functions can easily be operated remotely (low
voltage.
FIELD PROGRAMMABLE TIME DELAY:
•
Delay of lag function operation. Pump controller
time delay from 10 seconds to 3 minutes. Boiler
controller 30 seconds to 16 minutes.
The PSP, Pump Sequence Panels are available in four models, Model PSP-10 & PSP-12 are electronic
controllers housed in a 12″ W x 14″ H x 4″ D surface mount enclosure with key locking hinged door.
Models PSP-10 CM and PSP-12 CM are electronic controllers mounted on a 10.5″ W 2 14″ H steel
mounting plate for incorporation into a custom control panel. The PSP models also come with two
different output relay contact ratings, PSP-10 and PSP-10CM models have contacts rated for 15 A. at
120/220 VAC, and the PSP-12 and PSP-12 CM contacts are rated for 30A at 120/220 VAC.
Model Numbers are:
PSP-10 and PSP-10CM*
PSP-12 and PSP-12CM*
The BSP, Boiler Sequence Panels, controllers are also available with and without surface mount
enclosures. The Model BSP-15 controller is housed in a 12″ W x 14″ H x 4″ D surface mount
enclosure with key locking hinged door and BSP-15 CM controller is mounted on a 10.5″ W x 14″ H
steel mounting plate. Both models have an output relay contact rating of 15A at 120/220VAC.
Model Numbers are:
BSP-15 and BSP-15CM* *CM=Custom mount (controller mounted on steel plate
for incorporation into custom panel.)
TIMING:
All PSP-10 and 12 controllers are shipped from the factory with a 30 seconds delay and all BSP-15
controllers are shipped from the factory with a 6 minutes delay unless other time delay period is
requested. The time delay period starts when the outdoor air thermostat calls for pump/boiler to start,
or if the On-Off-Auto switch is switched to “On”. If the pump/boiler does not proof operation within
the time delay period then the standby pump/boiler is turned on by the controller.
TOXALERT INTERNATIONAL, Inc., PO Box 159, Mound, MN. 55364 PHONE: (952) 472-4541 • FAX: (952) 472-4960
www.toxalert.com

SEQUENCE OF OPERATION (PUMP SEQUENCE):
In circulating pump applications, two circulating pumps are ordinarily used in the water line, a lead or main operating pump
and a standby or backup pump. The “Lead pump” manual selector (S3) is placed in either the “R-1” or “R-2” position for
selection of the lead pump. The green LED indicates a “Flow-Normal” condition whenever either pump P-1 or P-2 is
operating normally. If the lead pump fails to operate the SPDT pressure differential or flow switch (supplied by others)
power the time delay circuit. If the flow is interrupted for more than 30 seconds (adjustable 10 seconds to 4 minutes), the
time delay relay will simultaneously deenergize the lead pump, energize the standby pump, activate the red “LEAD Pump
Failure”LED and trigger the remote alarm circuitry. A set of form C alarm contacts are brought out to the low voltage
terminal strip for remote alarm indication. 24VAC (30VA max.) can be picked up from the terminals “H” and “N” on TB-1
and fed through the alarm contacts to power a remote alarm device(s).
After an alarm indication and after the cause of the interruption has been eliminated, by repairing or replacing the lead pump,
the square red “Reset” button (S2) on the P.C. board, must be depressed to reestablish the selected lead/standby sequence,
turn off the red “lead Pump Failure” LED, and reset the remote alarm contacts. The continuous indication of the green
“Function Normal” LED again indicates lead pump operation.
The “LEAD/LAG” manual selector switch (S3) mounted on the P.C. board can be placed in either the “R-1” or “R-2”
position. In case of lead pump “failure”, the sequence will always index to the standby pump; P-2 or P-1, no matter which
pump is selected as the lead pump. In the event of power failure, the sequence will immediately start the lead pump when
power is restored. If the lead pump has failed, the standby pump will begin operating after the 30 second flow interruption.
SEQUENCE OF OPERATION (BOILER SEQUENCE):
The sequence of operation for the boiler controller is the same as for the pump controller except that the delay time is 6
minutes (standard) rather than 30 seconds for the pump sequence. Also, the proof of operation device, pressure sensor,
thermostat, or other proof of operation device (supplied by others) would be different from the pump flow proving device.
MOUNTING:
The Toxalert Lead/Lag controllers with cabinets may be mounted on the wall and is not position sensitive. The CM –
(customer mounted) controllers can be mounted in any custom control panel and will require approximately 10.5”W x
12.5”H x 3.0” D.
WIRING:
The sequencer is provided with line voltage power supply connections and pump relay connections in the top of the cabinet.
A low voltage, eight station terminal strip is located on the bottom of the P.C. board to connect the outdoor air thermostat, the
SPDT flow (or operations) indication device and optional remote alarm Panel(s). The Pump Sequence panels are assembled
to permit low voltage wiring to enter through the bottom. If the Lead/Lag and/or the ON-OFF-AUTO switches are to be
remotely mounted they can be wired with wire as small as #18 and may be up to 200 feet from its controller. All wiring must
be in accordance with applicable national and local electrical codes.
REMOTE LEAD/LAG OPERATION:
The Lead/Lag function can easily be accomplished by mounting a SPST switch in a remote location. The wiring is 24 VAC
and will require a switch that can switch .5A. Wire the remote switch across terminals H and LL of TB2 mounted in the
upper left corner of the printed circuit board. Cut jumper J-2 to disable the board mounted Lead/Lag switch. When the
remote Lead/Lag switch is in the open position, Relay #1 will control the lead equipment. With the switch closed, relay #2
will control the lead equipment and relay #1 will control its standby equipment.
REMOTE ON-OFF-AUTO:
Remote ON-OFF-AUTO can easily be accomplished by mounting a DPDT switch with ON-OFF-AUTO action, in a remote
location. The wiring is 24 VAC and will require a switch than can switch .5A. Wire the remote ON-OFF-AUTO switch as
described. A spare terminal with the neutral (N) side of 24 VAC is furnished on TB1. Wire (N) terminal to common of
remote switch. The auto side of the remote switch is to be wired to terminal 1 of TB4, and the on side to terminal 2 of TB4.
Cut jumper J1 and J3 to deactivate the PC board AUTO-OFF-ON switch.
TOXALERT INTERNATIONAL, Inc., PO Box 159, Mound, MN. 55364 PHONE: (952) 472-4541 • FAX: (952) 472-4960
www.toxalert.com

TABLE #1 TABLE #2
PSP-10 & PSP-12
TR VALUES IN OHMS RESULTING TIME DELAY
100K 10 seconds
300K 30 seconds **
620K 1 minute
1.2 meg 2 minutes
1.8 meg 3 minutes
2.4 meg 4 minutes
TR VALUES IN OHMS RESULTING TIME DELAY
BSP-15 & BSP-15CM
100K 30 seconds
200K 1 minute
360K 2 minutes
560K 3 minutes
750K 4 minutes
910K 5 minutes
1.2 meg 6 minutes **
1.3 meg 7 minutes
1.5 meg 8.25 minutes
1.8 meg 10 minutes
2.0 meg 11 minutes
3.0 meg 16 minutes
* TR resistors are mounted on the Timing Registor (TR) terminal strip (TB3) which is mounted on the P.C. board. ⅛ or ¼
watt resistors may be used.
** Time delay of standard units.
REQUIRED AUXILIARY EQUIPMENT (Supplied by Others)
A) SPDT Differential Pressure Switch or Flow Switch
Suggest: Robertshaw PF-126 Floating D Differential Pressure switch or
Penn P74FA-5 pressure Differential Switch.
B) Outside air thermostat for “AUTOMATIC” operation.
Suggest: Honeywell T675, or Columbus Electric LB100 (SPST) or LB200 (DPST) remote bulb thermostats, or TC-100
series remote bulb controllers from Dynacon. Toxalert has controlling devices you need for application. Please call.
LEAD/LAG CONTROLLER EXTERNAL WIRING
TOXALERT INTERNATIONAL, Inc., PO Box 159, Mound, MN. 55364 PHONE: (952) 472-4541 • FAX: (952) 472-4960
www.toxalert.com