the Inlet Nozzle, a high velocity jet is
formed that impinges on the Impeller,
causing the Impeller and the Striker
to rotate. With each rotation, the free
swinging Striker Ring hits the Gong and
sounds the alarm. The spent water is
then drained through the 1 in. outlet.
The alarm will sound as long as water
is flowing into the system and flowing
to the Water Motor Alarm. Water in the
alarm line will automatically drain back
through the orifice, which is also pro-
vided in the trim of the waterflow detec-
tion valve.
The Water Motor Alarm does not have
to be reset after an operation. However,
if the alarm was silenced during oper-
• 3/4 in. Check Valve with 3/32 in.
orifice (P/N 52-403-1-005)
Strainers must be located at the alarm
outlet in the trim of each of the water-
flow detection valves. Check valves
must be located between each strainer
and the interconnection with the alarm
line from another system.
Operation
Upon operation of the alarm check,
dry pipe, deluge, or preaction valve to
which the TYCO Model WMA-1 Water
Motor Alarm is connected, water will
flow to the Water Motor and through
the Inlet Nozzle. As water flows through
Item 9.
Drain water must be directed to
prevent accidental damage to property
or danger to persons when the alarm is
operating or thereafter.
Item 10.
The alarm line drain, at the
waterflow detection valve, must be
maintained at a minimum temperature
of 40°F (4°C).
Item 11.
A single Water Motor Alarm
may be connected to the alarm lines
from a maximum of three separate fire
protection systems. However, when
two or three alarm lines are intercon-
nected, each alarm line must be pro-
vided with the following:
• 3/4 in. Model WM-1 Y-Strainer
(P/N 52-271-1001)
TFP921
Page 2 of 4
FIGURE 1
MODEL WMA-1 WATER MOTOR ALARM
ASSEMBLY
1
2
4
5
7
3
6
8
(a)
(a)
Water Motor
92-630-1-012
NR
NR
Support Washer
Drive Shaft
Drive Shaft Sleeve
Gong Mount
See (a)
Striker
Gong
Red Gong Repair
Cap Nut
NO. DESCRIPTION
REF.
92-630-1-025
6, 7 (red), and 8
Kit includes items:
NR: Not Replaceable
NR
NR
See (a)
See (a)
6, 7 (alum.), and 8
Kit includes items:
Aluminum Gong Repair
92-630-2-025
1
1
1
1
QTY.
1
1
1
1
1
1
.
. . . . . .
. . . . . . .
. . . . . . . . . . .
. . .
. . .
. . . . . .
. . . . . . . . . . . .
. . . . . . . . .
. .
IMPELLER
NOZZLE
INLET
DRAIN
INTERNAL VIEW OF
WATER MOTOR (ITEM 1)
3
4
1
2
5
7
8
6
SPACER
COUPLING
COUPLING
3/4" NPS
STRIKER
SHAFT
BEARING
RING
STRIKER
STRIKER ARM
CROSS-SECTION VIEW
OF STRIKER (ITEM 6)
