IM 778 / Page 21
Pump Restart Relay Kit P/N 061419001
Used as an option with the Mark IV/AC board, the pump
restart relay kit provides a means to alert the loop water
controller that water flow is required by a WSHP so that the
system pump can be started. This option is typically used in
installations where the pump may be shut off when there is
no need for water flow (i.e. temperature OK, etc.). Typically
only one pump restart relay kit is required per installation as
up to 200 Mark IV/AC boards can be “daisy-chained”
together.
The Mark IV/AC “P” terminal is used to determine WSHP
compressor operation. Wired as shown below, when com-
pressor operation is required, the Mark IV/AC “P” terminal
will change state causing a contact closure between termi-
nal 58 and 64 signaling the loop water control (LWC) panel
to restart the loop pump if Off.
The pump restart relay kit is typically mounted within one
WSHP or within the LWC panel, whichever is more conve-
nient, diagrams are provided below for each location. To
install the relay, remove the cover on the double-faced tape
provided on the relay and attach the relay either to the
inside of the LWC panel (adjacent to circuit breaker CB1
and terminal block TB3) or in the WSHP control box (in a
convenient location), then wire as shown below.
WSHP Mark IV/AC Board Low Voltage Terminal Strip
Pump
Restart
Relay
7
6
5
4
3
2
1
O W2 G W1 Y1 F
E
L
U
A
P
V
R
C
Loop
Water
Controller
Terminals
Daisy chain to other Mark
IV/AC board “P” and “C”
terminals
64
58
65
WSHP Mark IV/AC Board Low Voltage Terminal Strip (Circuit 1)
Pump
Restart
Relay
7
6
5
4
3
2
1
O W2 G W1 Y1 F
E
L
U
A
P
V
R
C
Loop
Water
Controller
Terminals
Daisy chain to other Mark
IV/AC board “P” and “C”
terminals
64
58
Wiring Pump Restart Relay when Installed within the LWC Panel
Wiring Pump Restart Relay when Installed within a WSHP Control Box
