INSTALLATION INSTRUCTIONS
FOR SYMCOM'S
MODEL ALT
BE SURE POWER IS DISCONNECTED PRIOR TO INSTALLATION!!
FOLLOW NATIONAL, STATE AND LOCAL CODES!
The Model ALT alternating relay is used to
alternate between two loads. It is commonly
used in duplex pumping applications to
balance the runtime of both pumps. The
voltage must be specified in the ALT part
number—Table 1 identifies all available
Model ALTs.
ALT-24-S
ALT-24-X
ALT-24-S-SW
ALT-24-X-SW
ALT-115-S
ALT-115-X
ALT-115-S-SW
ALT-115-X-SW
ALT-230-S
ALT-230-X
ALT-230-S-SW
ALT-230-X-SW
20–26VAC, SPDT relay
20–26VAC, DPDT relay
20–26VAC, SPDT relay w/ manual/automatic switch
20–26VAC, DPDT relay, w/ manual/automatic switch
95–125VAC, SPDT relay
95–125VAC, DPDT relay
95–125VAC, SPDT relay, w/ manual/automatic switch
95–125VAC, DPDT relay, w/ manual/automatic switch
195-250VAC, SPDT relay
195–250VAC, DPDT relay
195–250VAC, SPDT relay, w/ manual/automatic switch
195–250VAC, DPDT relay, w/ manual/automatic switch
TABLE 1: ALT Model Numbers
MODEL ALT-S
The Model ALT-S has a single-pole, double-throw output relay and is used in
single high-level float applications. When the float switch opens, the alternating
relay changes state forcing the other pump to run the next time the float closes.
1
8
2 3
7 6
SUPPLY
4
5
PILOT
DEVICE
CONNECTIONS (MODEL ALT-S)
1.
Mount the Model OT08 octal socket in a convenient location inside the pump control panel.
2.
Connect one of the pump's magnetic contactor coils (#1) between socket terminal 2 and L1 of the
power supply (see Figure 1).
3.
Connect the other pump's magnetic contactor coil (#2) between socket terminal 8 and L1.
4.
Connect the power supply L1 to socket terminal 3 and L2 to terminal 4.
5.
Connect socket terminals 1 and 5 to one side of the pilot device (pressure switch, float
switch or other isolated contact).
6.
Connect the unconnected side of the pilot device to L2.
L1 L2
7. Plug the Model ALT into the socket.
L2
L1
MAG. COIL
#1
NC
C
2 3
1
4
NO 8
7 65
PRESSURE SWITCH,
FLOAT SWITCH OR
OTHER ISOLATED
CONTACT
MAGNETIC
CONTACTOR
#1
MAGNETIC
CONTACTOR
#2
PUMP
#1
PUMP
#2
MAG. COIL
#2
FIGURE 1: Typical Wiring Diagram for the Model ALT-S
222 Rapid
Disk Drive,
City, SD 57701
2880 North Plaza Drive,
City,Rapid
SD 57702
843-8848
www.symcom.com
(800) 843-8848(800)
· (605)
348-5580
www.symcom.com
MODEL ALT-X
The Model ALT-X has an internal double-pole, double-throw, cross-connected
relay and is used in dual high-level float applications. The pumps alternate as
in the ALT-S version, but the cross-connected relay configuration allows both
pumps to run simultaneously when both the lead and lag floats are closed.
PILOT
DEVICE
1
8
2 3
7 6
4
SUPPLY
5
CONNECTIONS (MODEL ALT-X)
1.
Mount the Model OT08 octal socket in a convenient location inside the pump control panel.
2.
The control circuit should be separately fused to avoid disabling the control circuit when one pump is
disconnected for service.
3.
Connect Pump #1’s magnetic contactor coil between socket terminal 8 and L2 of the power supply.
4.
Connect Pump #2’s magnetic contactor coil between socket terminal 7 and L2 of the power supply.
5.
Connect the LEAD pilot device, S1 (pressure switch, float switch or other isolated contact), between
socket terminals 1 and 3. Each time S1 opens, the relay changes state forcing the other pump to run
the next time the float closes.
6.
Connect the LAG pilot device, S2, between socket terminals 2 and 3.
7.
Connect L2 of the power supply to socket terminal 6 and L1 to terminal 3.
8.
Plug the Model ALT into the socket.
MODEL ALT-X
S1
LEAD
F1
1
S2
8
LAG
2
7
3
6
L1
4
F2
L2
5
F1 & F2:
1–2A TYPICAL SIZE
FOR CONTACTOR COILS
OPTIONAL
PUMPSAVER® PUMP
PROTECTOR
F3
L1
PUMP
#1
F4
L2
MAGNETIC CONTACTORS
F5
L1
PUMP
#2
F6
L2
OPTIONAL
PUMPSAVER® PUMP
PROTECTOR
F3–F6:
SIZE FOR INDIVIDUAL
PUMP APPLICATION
FIGURE 2: Typical Wiring Diagram for the Model ALT-X
MANUAL/AUTOMATIC SWITCH
The ALT is also available with a built-in switch (-SW option) that can be used to manually force one pump to run every
time the float closes. This is useful when a pump has been removed for repair or for test purposes. In the case of the
Model ALT-X-SW, the switch essentially forces one pump to be the lead pump, while still allowing the second pump to
run if both floats are closed.