CAUTION
Risk of Environmental and Property Damage
Coil and secure excess capillary tubing away from
contact with sharp or abrasive objects or surfaces.
Vibration and sharp or abrasive objects in contact
with capillary tubes can cause damage that may
result in release of the chemical charge in the
sensing element, which may result in damage to the
environment or property.
CAUTION
Risk of Property Damage
Do not dent or deform the sensing bulb. Dents or
deformations in the sensing bulb can change the
calibration, may cause the control to operate at
temperatures other than the setpoint, and may result
in other property damage.
Important:
• When you drill holes or drive screws to mount the
sensing elements, be careful not to puncture or
damage hydronic coils.
• Use only the mounting screws supplied with the
Universal Mounting Bracket to avoid damage to
the internal components. Be careful not to distort
or bend the control case when you mount the
control to an uneven surface. The use of other
screws or bending the control case voids the
warranty.
• Locate the control case and bellows where the
ambient temperature is always warmer than
the setpoint. The control operates only from
the lowest temperature along any 14 in. to 16
in. (356 mm to 406 mm) length of the sensing
element.
• Locate low temperature cutout controls in areas
protected from the effects of weather. If you
mount the control in an area that is exposed to
the weather or other wet environments, equip it
with an outdoor enclosure.
• It is important to mount the low temperature
cutout control in the correct location. Expose the
capillary to all areas on the coil where a risk of low
temperatures is present.
Observe the following guidelines when you mount A11
Series low temperature cutout controls.
• Mount the control upright in an accessible location,
where the control body, capillary tube, and sensing
bulb are not subject to damage, and the control is in
the highest possible position of the entire installation.
• Mount the control upstream from mixed air or chilled
water coils.
• Mount the control downstream from preheat coils.
• Mount the control upright on flat, vertical, or horizontal
surfaces using accessory brackets. These controls have
NEMA 1 enclosures.
• Mount the capillary in a serpentine fashion so that it
slopes gently downhill at an angle not greater than 5°.
Do not permit any dips, bends, or kinks in the capillary,
and install the last segment within 6 in. (152.4 mm) of
the bottom of the coil.
Figure 4: Control capillary orientation
Table 3: Control capillary orientation
Callout
Description
A
Correct. Orient the capilliary horizontally.
B
Incorrect. Do not orient the capilliary
vertically.
Mounting in an accessible location
Before you begin:
Sometimes, the coil face offers nothing that can hold
the tie-wrapped sensing element. In these cases, use
1/2 in. (13 mm) EMT, hard copper tubing, or Unistrut to
build supports to fasten the sensing element. Fasten the
sensing element to fixed supports to hold the element
in place and prevent movement in the air stream. Field-
fabricated supports often take the form of a rack with
vertical supports. To determine the proper location, see
1. Determine the best mounting location for the low
temperature cutout control. Locate the control
as high as possible on the side of the duct or on
a nearby wall, panel, or structural support. The
optimum mounting position is with the element
bellows pointing down.
2. When you mount the control directly to a flat
vertical surface, insert two screws or bolts through
the two outer holes on the back of the control case.
3. When you mount the control to a flat horizontal
surface, use the two inner holes with the mounting
bracket and the supplied screws.
4. Build and install any field-fabricated supports that
are necessary to hold the sensing element in place.
5. Use the control’s mounting bracket as a template
to mark the location for the mounting screws.
6. Drill an 5/16 in. (8 mm) entry hole for the sensing
element.
7. Feed the entire length of the sensing element
through the entry hole.
A11 Series Low Temperature Cutout Control Installation Guide
3
