2-31. COLD WEATHER OPERATION. Take special care of the ROWPU in cold weather. Parts of the ROWPU will be
damaged if they freeze. If the temperature is expected to drop below 32°F (0°C), the ROWPU must be protected.
Precautions must be taken. The winter kit must be used.
a. Limitations. Freeze up will disrupt operation, perhaps for several days, and may cause damage. Limitations should
not be exceeded.
(1) Minimum deployment temperature: -25°F (-32°C).
(2) Maximum shutdown time without draining exterior hoses: 15 minutes.
(3) Maximum shutdown time without power and without draining raw water and distribution pumps: 15 minutes.
(4) Maximum shutdown time at -25°F (-32°C) without heaters operating before freeze up problems begin:
(a) Without draining and purging the filters and chemical systems: 30 minutes (doors closed).
(b) Without draining the RO vessels: 30 minutes (doors closed).
(c) Fully drained and purged: one hour (doors closed).
(5) Maximum shutdown time with one space heater operating from the diesel generator batteries without
excessive battery discharge: 1 hour.
(6) Items which will be damaged if allowed to freeze:
Color test kit.
Available chlorine color test kit.
RO elements, if not removed from vessels and properly drained.
(7) Minimum storage temperature for ROWPU except items subject to freeze damage: -28°F (-37°C).
Refer to FM 10-52 Field Water Supply manual before performing the following steps.
(8) Preparation for winter deployment.
Move ROWPU to warm area.
Load RO elements.
Move raw water and distribution pump pallets to accessible area.
Move raw water and distribution pump covers to accessible area.
The 24 VDC cable connector and diesel fuel inlet are on an access panel on the
generator end of the van.
Install 24 VDC cable from van to generator.
(f) Connect diesel fuel line from generator fuel out fitting to diesel fuel inlet.
(g) Perform PMCS on generator for cold operation.
(h) Perform PMCS on high pressure pump assembly.
(i) Stan van diesel heater no. 2.
(9) Winter deployment.
Site van as close to water source as possible.
Install ground rods and ground cables.
Start generator and supply power to ROWPU.
Start high pressure pump assembly electric heater.