Operation; Installation; Location; Mounting The Subbase - Honeywell T874R Installation Instructions Manual

T874R THERMOSTATS AND Q674L SUBBASES

OPERATION

O n a 2 - h e a t t h e r m o s t a t , t h e t w o s t a g e s o f h e a t
s e q u e n t i a l l y a s t h e t e m p e r a t u r e d r o p s .
m e r c u r y s w it c h in it ia t in g a c a ll f o r h e a t o r c o o l.
T h e r e is a b o u t 1 ° F ( 0 . 6 ° C ) b e t w e e n s t a g e s s o t h e s e c ­
o n d s t a g e m a k e s o n ly w h e n t h e f ir s t s t a g e c a n n o t h a n d le
1 0 6
t h e lo a d . T h e ° F ( . ° C ) is r e f e r r e d to a s t h e
differential
T h e lig h t e m it t in g d io d e s ( L E D ) o n t h e s u b b a s e lig h t w h e n
s o m e t h i n g s p e c if ic h a p p e n s w it h in t h e s y s t e m . W h e n a n
L E D lig h ts , r e f e r t o t h i s lis t f o r t h e m e a n in g :
E M . H T .: E m e r g e n c y h e a t is o p e r a t in g . T h e c o m p r e s ­
s o r h a s f a ile d , a n d t h e h e a t p u m p is n o t o p e r a t in g .
L E D lig h t s w h e n s y s t e m s w it c h is p la c e d in t h e
E M . H T . p o s it io n b y t h e h o m e o w n e r .
A U X . H T . : A u x i lia r y h e a t is o p e r a t in g , w h ic h m e a n s t h e
w e a t h e r is s o c o ld t h a t t h e h e a t p u m p c a n n o t h a n d le
t h e lo a d .
C H E C K : S y s t e m n e e d s t o b e c h e c k e d . S e e h e a t in g
s y s - t e m in s t r u c t i o n s f o r s p e c if ic m e a n in g .
N O T E : L E D s a r e n o t f ie ld r e p la c e a b le o r a d d a b le .
®) RECYCLING NOTICE
T h is c o n t r o l c o n t a in s m e r c u r y in a s e a le d tu b e . D o n
p la c e c o n t r o l in t h e tr a s h a t t h e e n d o f its u s e fu l life.
If t h is c o n t r o l is r e p la c in g a c o n t r o l t h a t c o n t a in s
m e r - c u r y in a s e a le d t u b e , d o
c o n t r o l in t h e t r a s h .
C o n t a c t y o u r lo c a l w a s t e m a n a g e m e n t a u t h o r it y f o r
in s t r u c t i o n s r e g a r d in g r e c y c lin g a n d t h e p r o p e r
d i s p o s a l o f t h i s c o n t r o l, o r o f a n o ld c o n t r o l
c o n t a in i n g m e r c u r y in a s e a le d tu b e .

INSTALLATION

When Installing this Product...
1 . R e a d t h e s e in s t r u c t i o n s c a r e f u lly . F a ilu r e t o f o l lo w
t h e m c o u ld d a m a g e t h e p r o d u c t o r c a u s e a h a z a r d ­
o u s c o n d it io n .
2 . C h e c k t h e r a t in g s g iv e n in t h e in s t r u c t i o n s a n d o n
t h e p r o d u c t t o m a k e s u r e t h e p r o d u c t is s u it a b le f o r
y o u r a p p lic a t io n .
3 . I n s t a lle r m u s t b e a t r a in e d , e x p e r ie n c e d s e r v ic e
t e c h n ic ia n .
4 . A f t e r i n s t a ll a t io n is c o m p le t e , c h e c k o u t p r o d u c t
o p e r a t i o n a s p r o v id e d in t h e s e in s t r u c t io n s .
69-0392—9
m ake
M a k e
r e f e r s to t h e
in te rs ta g e
o t
n o t
p la c e y o u r o ld
2
A CAUTION
1. D is c o n n e c t p o w e r s u p p ly to p r e v e n t e le c t r ic a l
s h o c k o r e q u ip m e n t d a m a g e .
2 . T o p r e v e n t in t e r f e r e n c e w it h t h e t h e r m o s t a t
lin k a g e , k e e p w ir e le n g t h t o a m i n im u m a n d
r u n w ir e s a s c lo s e a s p o s s ib le t o t h e s u b b a s e .
3 . P u s h e x c e s s w i r e b a c k in t o t h e h o le a n d p lu g
h o le t o p r e v e n t d r a f t s f r o m a f f e c t i n g t h e r m o ­
s t a t o p e r a t io n .
4 . D o n o t o v e r t i g h t e n t h e r m o s t a t c a p t iv e
m o u n t in g s c r e w s b e c a u s e d a m a g e to
s u b b a s e t h r e a d s c a n re s u lt.
5 . D o n o t s h o r t a c r o s s c o il t e r m i n a l s o n h e a t in g
r e la y o r g a s v a lv e . T h i s c a n b u r n o u t t h e
t h e r m o s t a t h e a t a n t ic ip a to r .
6
. N e v e r in s t a ll m o r e t h a n o n e w ir e p e r t e r m in a l
u n le s s f a c t o r y - s u p p l i e d ju m p e r w it h s p a d e
t e r m in a l s is u s e d .
IMPORTANT
Thermostats are calibrated a t the factory using
subbase m ounted a t true le v e l Inaccurate
subbase levelin g causes the actual temperature
to deviate from the setpoint temperature.

Location

I n s ta ll t h e t h e r m o s t a t a b o u t 5 f t ( 1 . 5 m ) a b o v e t h e f lo o r in
a n a r e a w it h g o o d a i r c ir c u la t io n a t a v e r a g e t e m p e r a t u r e .
D o n o t in s t a ll t h e t h e r m o s t a t w h e r e it c a n b e a f f e c t e d b y :
— d r a f t s o r d e a d s p o t s b e h in d d o o r s a n d in c o r n e r s .
— h o t o r c o ld a ir f r o m d u c t s .
— r a d ia n t h e a t f r o m s u n o r a p p lia n c e s .
— c o n c e a l e d p ip e s a n d c h im n e y s .
— u n h e a t e d ( u n c o o le d ) a r e a s s u c h a s a n o u t s id e w a ll
b e h in d t h e t h e r m o s t a t .

Mounting The Subbase

T h e t h e r m o s t a t s u b b a s e c a n b e m o u n t e d o n a v e r t ic a l
o u t le t b o x , h o r iz o n t a l o u t le t b o x o r d i r e c t l y o n t h e w a ll.
1 . If y o u m u s t m o u n t t h e s u b b a s e o n a v e r t ic a l o u t le t
b o x , o r d e r H o n e y w e ll 1 9 3 1 2 1 A A d a p t e r A s s e m b ly .
S e e F ig . 1 . T h e a s s e m b ly in c lu d e s a n a d a p t e r r in g ,
t w o s c r e w s a n d a c o v e r p la t e to c o v e r m a r k s o n th e
w a ll. In s t a ll t h e r in g a n d c o v e r p la t e o n t h e v e r t ic a l
o u t le t b o x .
F o r a w a ll in s t a ll a t io n , h o ld s u b b a s e in p o s it io n a n d
m a r k h o le s f o r a n c h o r s . S e e F ig . 2 . O b t a in w a ll
a n c h o r s lo c a lly . B e c a r e f u l t h a t t h e w i r e s d o n o t fa ll
b a c k in to t h e w a ll o p e n in g . S e t a s id e s u b b a s e . D r ill
t w o 3 / 1 6 in . (5 m m ) h o le s a n d g e n t ly t a p a n c h o r s
in t o t h e h o le s u n t il f lu s h w it h t h e w a ll.